Transmit-receive point selection for coherent joint transmission

Abstract

Methods, systems, and devices for wireless communication are described. A user equipment (UE) may receive channel state information (CSI) reference signals (CSI-RSs) from a plurality of transmit receive points (TRPs), and may perform measurements on the CSI-RSs. The UE may then select a subset of the plurality of TRP to communicate with, and the UE may send an indication of the selected TRP in a CSI report. In some cases, the UE may indicate a common subset of TRP with which the UE may communicate on multiple layers, or the UE may indicate a respective subset of TRP with which the UE may communicate on each of the multiple layers. The UE may also provide additional information for the selected TRP in the CSI report. The selected TRP may then use the additional information provided in the CSI report to identify a suitable configuration for communicating with the UE.

Description

Technical Field

[0001] The following relates to wireless communications, including transmit / receive point selection for coherent joint transmission. Background Art

[0002] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, etc. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems (such as long term evolution (LTE) systems, advanced LTE (LTE-A) systems, or LTE-A Pro systems) and fifth generation (5G) systems (which may be referred to as new radio (NR) systems). These systems may employ techniques such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM).

[0003] A wireless multiple access communication system may include one or more base stations, each of which supports wireless communication of communication devices, which may be referred to as user equipment (UE). In some wireless communication systems, a UE may communicate with multiple transmit receive points (TRPs) to improve the reliability of communication. Improved techniques for supporting multi-TRP communication may be needed. Summary of the invention

[0004] The described technology relates to improved methods, systems, devices and apparatuses that support transmit receive point (TRP) selection for coherent joint transmission. A user equipment (UE) can receive a channel state information (CSI) reference signal (CSI-RS) from multiple TRPs and can perform measurements on the CSI-RS. The UE can then select a subset of multiple TRPs to communicate with, and the UE can send an indication of the selected TRP in a CSI report. In some cases, the UE can indicate a common subset of TRPs with which the UE can communicate on multiple layers, or the UE can indicate a corresponding subset of TRPs with which the UE can communicate on each of the multiple layers. The UE can also provide additional information for the selected TRP in the CSI report. The selected TRP can then use the additional information provided in the CSI report to identify a suitable configuration for communicating with the UE.

[0005] A method for wireless communication at a UE is described. The method may include receiving a channel state information reference signal from a set of multiple transmission reception points; sending a channel state information report based on receiving the channel state information reference signal, the channel state information report indicating a subset of transmission reception points selected from the set of multiple transmission reception points for communication with the UE; and communicating with the subset of transmission reception points based on sending the channel state information report.

[0006] An apparatus for wireless communication is described. The apparatus may include: a memory; a transceiver; and at least one processor of a UE, the at least one processor coupled to the memory and the transceiver. The at least one processor may be configured to receive a channel state information reference signal from a set of multiple transmission reception points; send a channel state information report based on receiving the channel state information reference signal, the channel state information report indicating a subset of transmission reception points selected from the set of multiple transmission reception points for communicating with the UE; and communicate with the subset of transmission reception points based on sending the channel state information report.

[0007] Another apparatus for wireless communication at a UE is described. The apparatus may include means for receiving a channel state information reference signal from a set of multiple transmission reception points; means for sending a channel state information report based on receiving the channel state information reference signal, the channel state information report indicating a subset of transmission reception points selected from the set of multiple transmission reception points for communication with the UE; and means for communicating with the subset of transmission reception points based on sending the channel state information report.

[0008] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to perform the following operations: receiving a channel state information reference signal from a set of multiple transmission reception points; sending a channel state information report based on receiving the channel state information reference signal, the channel state information report indicating a subset of transmission reception points selected from the set of multiple transmission reception points for communication with the UE; and communicating with the subset of transmission reception points based on sending the channel state information report.

[0009] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for the following actions: sending a bitmap indicating a subset of transmit reception points used for communicating with the UE in a channel state information report, where the size of the bitmap can be proportional to the size of the set of multiple transmit reception points.

[0010] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, a bitmap indicates a common subset of transmit-receive points used to communicate with a UE on a set of multiple layers. In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, a bitmap indicates a respective subset of transmit-receive points used to communicate with a UE on each layer in a set of multiple layers.

[0011] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving an indication of a configuration that indicates in a bitmap a common subset of transmit-receive points for communicating with the UE on a first set of multiple layers, or a corresponding subset of transmit-receive points for communicating with the UE on each layer in a second set of multiple layers.

[0012] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for the following actions: sending a common selection of a spatial domain basis for each transmission reception point in a subset of transmission reception points in a channel state information report for communicating with a UE on a set of multiple layers. Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for the following actions: sending a corresponding selection of a spatial domain basis for each transmission reception point in a subset of transmission reception points in a channel state information report for communicating with a UE on each layer in a set of multiple layers.

[0013] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the amount of spatial domain basis indicated in the channel state information report may be constant for each transmission reception point in the subset of transmission reception points. In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the amount of spatial domain basis indicated in the channel state information report for a transmission reception point in the subset of transmission reception points may be based on the transmission reception point.

[0014] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: receiving an indication of a configuration of a total amount of spatial domain bases to be indicated in a channel state information report; and sending in the channel state information report the amount of spatial domain bases included in the channel state information report for each transmitting receiving point in a subset of transmitting receiving points.

[0015] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for the following actions: in a channel state information report, based on the number of transmit-receive points selected for communicating with the UE on the layer, sending a corresponding number of selected frequency domain bases for each layer in a set of multiple layers.

[0016] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending a common selection of a spatial domain basis for each transmit-receive point in a subset of transmit-receive points in a channel state information report for each layer in a set of multiple layers for communicating with a UE.

[0017] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: sending in a channel state information report selected non-zero coefficients for precoding a first polarization at a first transmit-receive point in a subset of transmit-receive points, wherein the first polarization may be stronger than a second polarization at the first transmit-receive point; sending in a channel state information report first two or more differential amplitudes between the selected non-zero coefficients and the coefficients for precoding the second polarization at each transmit-receive point in the subset of transmit-receive points; and sending in a channel state information report a second one or more differential amplitudes between the selected non-zero coefficients and the coefficients for precoding at each transmit-receive point in the subset of transmit-receive points other than the first transmit-receive point.

[0018] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending in a channel state information report an indication of whether the first polarization or the second polarization may be stronger for each of the subset of transmit-receive points.

[0019] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending selected non-zero coefficients for precoding for a first polarization at a first transmission reception point in a channel state information report for a first transmission reception point in a subset of transmission reception points, and sending one or more differential amplitudes between the selected non-zero coefficients and the coefficients for precoding for a second polarization at the first transmission reception point in a channel state information report for the first transmission reception point.

[0020] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, communicating with a subset of transmit-receive points may include operations, features, components, or instructions for receiving a coherent joint transmission from the subset of transmit-receive points, wherein the phases of a set of multiple transmissions forming the coherent joint transmission may be controlled and coordinated by the subset of transmit-receive points.

[0021] A method for wireless communication at a network entity is described. The method may include sending a channel state information reference signal; receiving a channel state information report based on sending the channel state information reference signal, the channel state information report indicating a subset of transmit reception points selected from a set of multiple transmit reception points for communicating with a UE; and communicating with the UE based on receiving the channel state information report.

[0022] An apparatus for wireless communication is described. The apparatus may include: a memory; a transceiver; and at least one processor of a network entity, the at least one processor coupled to the memory and the transceiver. The at least one processor may be configured to send a channel state information reference signal; receive a channel state information report based on sending the channel state information reference signal, the channel state information report indicating a subset of transmission reception points selected from a set of multiple transmission reception points for communicating with a UE; and communicate with the UE based on receiving the channel state information report.

[0023] Another apparatus for wireless communication at a network entity is described. The apparatus may include means for sending a channel state information reference signal; means for receiving a channel state information report based on sending the channel state information reference signal, the channel state information report indicating a subset of transmit reception points selected from a set of multiple transmit reception points for communicating with a UE; and means for communicating with the UE based on receiving the channel state information report.

[0024] A non-transitory computer-readable medium storing code for wireless communication at a network entity is described. The code may include instructions executable by a processor to: transmit a channel state information reference signal; receive a channel state information report based on the transmitted channel state information reference signal, the channel state information report indicating a subset of transmit reception points selected from a set of multiple transmit reception points for communicating with a UE; and communicate with the UE based on the received channel state information report.

[0025] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for the following actions: receiving a bitmap in a channel state information report indicating a subset of transmit reception points used to communicate with the UE, wherein the size of the bitmap may be proportional to the amount of the set of multiple transmit reception points.

[0026] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, a bitmap indicates a common subset of transmit-receive points used to communicate with a UE on a set of multiple layers. In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, a bitmap indicates a respective subset of transmit-receive points used to communicate with a UE on each layer in a set of multiple layers.

[0027] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for the following actions: sending an indication of a configuration that is used to indicate in a bitmap a common subset of transmit-receive points for communicating with the UE on a first set of multiple layers, or a corresponding subset of transmit-receive points for communicating with the UE on each layer in a second set of multiple layers.

[0028] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for the following actions: receiving a common selection of a spatial domain basis for each transmission reception point in a subset of transmission reception points in a channel state information report for communicating with a UE on a set of multiple layers. Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for the following actions: receiving a corresponding selection of a spatial domain basis for each transmission reception point in a subset of transmission reception points in a channel state information report for communicating with a UE on each layer in a set of multiple layers.

[0029] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the amount of spatial domain basis indicated in the channel state information report may be constant for each transmission reception point in the subset of transmission reception points. In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the amount of spatial domain basis indicated in the channel state information report for a transmission reception point in the subset of transmission reception points may be based on the transmission reception point.

[0030] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: sending an indication of a configuration of the total amount of spatial domain bases to be indicated in a channel state information report; and receiving in the channel state information report the amount of spatial domain bases included in the channel state information report for each transmitting reception point in a subset of transmitting reception points.

[0031] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for the following actions: in a channel state information report, based on the number of transmit / receive points selected for communicating with the UE on the layer, receiving a corresponding number of selected frequency domain bases for each layer in a set of multiple layers.

[0032] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving, in a channel state information report for each layer in a set of multiple layers, a common selection of a spatial domain basis for each transmit-receive point in a subset of transmit-receive points for communicating with a UE.

[0033] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: receiving in a channel state information report selected non-zero coefficients for precoding a first polarization at a first transmit-receive point in a subset of transmit-receive points, wherein the first polarization may be stronger than a second polarization at the first transmit-receive point; receiving in the channel state information report first two or more differential amplitudes between the selected non-zero coefficients and the coefficients for precoding the second polarization at each transmit-receive point in the subset of transmit-receive points; and receiving in the channel state information report a second one or more differential amplitudes between the selected non-zero coefficients and the coefficients for precoding at each transmit-receive point in the subset of transmit-receive points other than the first transmit-receive point.

[0034] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving in a channel state information report an indication of whether the first polarization or the second polarization may be stronger for each of the subset of transmit-receive points.

[0035] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving selected non-zero coefficients for precoding a first polarization at a first transmission reception point in a channel state information report for a first transmission reception point in a subset of transmission reception points, and receiving one or more differential magnitudes between the selected non-zero coefficients and the coefficients for precoding a second polarization at the first transmission reception point in the channel state information report for the first transmission reception point.

[0036] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, communicating with a UE may include operations, features, components, or instructions for the following actions: sending at least one transmission from a set of multiple transmissions forming a coherent joint transmission to the UE, wherein the phases of the set of multiple transmissions forming the coherent joint transmission can be controlled and coordinated by a subset of the transmission receiving points. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 An example of a wireless communication system supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is illustrated.

[0038] Figure 2 An example of non-coherent joint transmission according to one or more aspects of the present disclosure is illustrated.

[0039] Figure 3 An example of coherent joint transmission according to one or more aspects of the present disclosure is illustrated.

[0040] Figure 4 Examples of orientations of different antenna panels for coherent joint transmission in accordance with one or more aspects of the present disclosure are illustrated.

[0041] Figure 5 An example of a precoding matrix indicated in a channel state information (CSI) report for multiple layers in accordance with one or more aspects of the present disclosure is illustrated.

[0042] Figure 6 An example of a wireless communication system supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is illustrated.

[0043] Figure 7 An example of layer-specific selection of a spatial domain (SD) basis according to one or more aspects of the present disclosure is illustrated.

[0044] Figure 8 An example of a process flow supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is illustrated.

[0045] Fig. 9 and Fig.10 A block diagram of a device supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown.

[0046] Fig.11 A block diagram of a communication manager supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown.

[0047] Fig.12A diagram of a system including devices supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown.

[0048] Fig.13 and Fig.14 A block diagram of a device supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown.

[0049] Fig.15 A block diagram of a communication manager supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown.

[0050] Fig.16 A diagram of a system including devices supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown.

[0051] Fig.17 and Fig.18 A flowchart illustrating a method for supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0052] In some wireless communication systems, a user equipment (UE) can communicate with multiple transmit receive points (TRPs) to improve the reliability of communications. For example, when operating in a multi-TRP operating mode, the UE can receive the same downlink data from multiple TRPs, resulting in improved reliability (e.g., a higher chance of the UE receiving the data). In such systems, the TRP can send a channel state information (CSI) reference signal (CSI-RS) to the UE, and the UE can perform measurements on the CSI-RS to identify a suitable configuration for communicating with the TRP. The UE can also send a CSI report to a network entity so that the network entity can identify a suitable configuration at the TRP for communicating with the UE. However, in some cases, as the number of TRPs with which the UE can be configured to communicate increases, the overhead of the CSI report also increases, resulting in increased power consumption and processing at the UE in addition to inefficient utilization of resources.

[0053] As described herein, a wireless communication system may support an efficient technique at a UE for selecting a TRP with which to communicate to minimize the overhead of CSI reporting. The UE may receive CSI-RS from multiple TRPs and may perform measurements on the CSI-RS. The UE may then select a subset of the multiple TRPs with which to communicate, and the UE may send an indication of the selected TRP in a CSI report. In some cases, the UE may indicate a common subset of TRPs with which the UE may communicate on multiple layers, or the UE may indicate a corresponding subset of TRPs with which the UE may communicate on each of the multiple layers. The UE may also provide additional information for the selected TRP in the CSI report. The selected TRP may then use the additional information provided in the CSI report to identify a suitable configuration for communicating with the UE.

[0054] First, various aspects of the present disclosure are described in the context of a wireless communication system. Examples of processes and signaling exchanges that support TRP selection for coherent joint transmission are then described. Various aspects of the present disclosure are further illustrated by apparatus diagrams, system diagrams, and flow diagrams relating to TRP selection for coherent joint transmission, and various aspects of the present disclosure are described with reference to these diagrams.

[0055] Figure 1 An example of a wireless communication system 100 supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is illustrated. The wireless communication system 100 may include one or more network entities 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a long term evolution (LTE) network, an advanced LTE (LTE-A) network, an LTE-A Pro network, a new radio (NR) network, or a network operating according to other systems and radio technologies (including future systems and radio technologies not explicitly mentioned herein).

[0056] The network entities 105 may be dispersed throughout a geographic area to form the wireless communication system 100, and may include devices in different forms or with different capabilities. In various examples, the network entities 105 may be referred to as network elements, mobility elements, radio access network (RAN) nodes, or network equipment, etc. In some examples, the network entities 105 and the UE 115 may communicate wirelessly via one or more communication links 125 (e.g., radio frequency (RF) access links). For example, the network entity 105 may support a coverage area 110 (e.g., a geographic coverage area) within which the UE 115 and the network entity 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area within which the network entity 105 and the UE 115 may support signal communications according to one or more radio access technologies (RATs).

[0057] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary or mobile, or both stationary and mobile at different times. The UEs 115 may be devices in different forms or with different capabilities. Figure 1 Some example UEs 115 are illustrated in FIG. 1. The UEs 115 described herein may be capable of communicating with various types of devices such as Figure 1 Communicating with other UEs 115 or network entities 105 as shown.

[0058] As described herein, a node of the wireless communication system 100 (which may be referred to as a network node or a wireless node) may be a network entity 105 (e.g., any network entity described herein), a UE 115 (e.g., any UE described herein), a network controller, an apparatus, a device, a computing system, one or more components, or another suitable processing entity configured to perform any of the techniques described herein. For example, the node may be a UE 115. As another example, the node may be a network entity 105. As another example, a first node may be configured to communicate with a second node or a third node. In one aspect of this example, the first node may be a UE 115, the second node may be a network entity 105, and the third node may be a UE 115. In another aspect of this example, the first node may be a UE 115, the second node may be a network entity 105, and the third node may be a network entity 105. In yet other aspects of this example, the first node, the second node, and the third node may be different relative to these examples. Similarly, references to UE 115, network entity 105, apparatus, device, computing system, etc. may include disclosure of UE 115, network entity 105, apparatus, device, computing system, etc. as nodes. For example, a disclosure that UE 115 is configured to receive information from network entity 105 also discloses that the first node is configured to receive information from a second node.

[0059] In some examples, the network entities 105 may communicate with the core network 130, or with each other, or both. For example, the network entities 105 may communicate with the core network 130 via one or more backhaul communication links 120 (e.g., according to S1, N2, N3, or other interface protocols). In some examples, the network entities 105 may communicate with each other directly (e.g., directly between each network entity 105) or indirectly (e.g., via the core network 130) via the backhaul communication links 120 (e.g., according to X2, Xn, or other interface protocols). In some examples, the network entities 105 may communicate with each other via midhaul communication links 162 (e.g., according to a midhaul interface protocol) or fronthaul communication links 168 (e.g., according to a fronthaul interface protocol) or any combination thereof. The backhaul communication links 120, midhaul communication links 162, or fronthaul communication links 168 may be or include one or more wired links (e.g., electrical links, optical fiber links), one or more wireless links (e.g., radio links, wireless optical links), etc. or various combinations thereof. UE 115 may communicate with core network 130 via communication link 155 .

[0060] One or more of the network entities 105 described herein may include or may be referred to as a base station 140 (e.g., a transceiver base station, a radio base station, an NR base station, an access point, a radio transceiver, a Node B, an evolved Node B (eNB), a next generation Node B, or a Gigabit Node B (any of which may be referred to as a gNB), a 5G NB, a next generation eNB (ng-eNB), a home Node B, a home evolved Node B, or other suitable terms). In some examples, the network entity 105 (e.g., a base station 140) may be implemented in an aggregated (e.g., monolithic, stand-alone) base station architecture, which may be configured to utilize a protocol stack physically or logically integrated within a single network entity 105 (e.g., a single RAN node, such as a base station 140).

[0061] In some examples, the network entity 105 may be implemented in a disaggregated architecture (e.g., a disaggregated base station architecture, a disaggregated RAN architecture) that may be configured to utilize a protocol stack that is physically or logically distributed between two or more network entities 105, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance), or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN)). For example, the network entity 105 may include one or more of the following: a central unit (CU) 160, a distributed unit (DU) 165, a radio unit (RU) 170, a RAN intelligent controller (RIC) 175 (e.g., a near real-time RIC (near RT RIC), a non-real-time RIC (non-RT RIC)), a service management and orchestration (SMO) 180 system, or any combination thereof. The RU 170 may also be referred to as a radio head, a smart radio head, a remote radio head (RRH), a remote radio unit (RRU), or a TRP. One or more components of the network entity 105 in the decomposed RAN architecture may be co-located, or one or more components of the network entity 105 may be located in distributed locations (e.g., separate physical locations). In some examples, one or more network entities 105 of the decomposed RAN architecture may be implemented as virtual units (e.g., virtual CU (VCU), virtual DU (VDU), virtual RU (VRU)).

[0062] The functional split between CU 160, DU 165, and RU 170 is flexible and may support different functionalities depending on which functions (e.g., network layer functions, protocol layer functions, baseband functions, RF functions, and any combination thereof) are performed at CU 160, DU 165, and RU 170. For example, a functional split of a protocol stack may be employed between CU 160 and DU 165 such that CU 160 may support one or more layers of a protocol stack and DU 165 may support one or more different layers of a protocol stack. In some examples, CU 160 may host higher protocol layer (e.g., layer 3 (L3), layer 2 (L2)) functionality and signaling (e.g., radio resource control (RRC), service data adaptation protocol (SDAP), packet data convergence protocol (PDCP)). The CU 160 may be connected to one or more DUs 165 or RUs 170, and the one or more DUs 165 or RUs 170 may host lower protocol layers, such as layer 1 (L1) (e.g., physical (PHY) layer) or L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU 160. Additionally or alternatively, a functional split of the protocol stack may be employed between the DUs 165 and RUs 170, such that the DUs 165 may support one or more layers of the protocol stack, and the RUs 170 may support one or more different layers of the protocol stack. The DUs 165 may support one or more different cells (e.g., via one or more RUs 170). In some cases, the functional split between CU 160 and DU 165 or between DU 165 and RU 170 may be within the protocol layer (e.g., some functions of the protocol layer may be performed by one of CU 160, DU 165, or RU 170, while other functions of the protocol layer are performed by different ones of CU 160, DU 165, or RU 170). CU 160 may be further functionally split into CU control plane (CU-CP) and CU user plane (CU-UP) functions. CU 160 may be connected to one or more DUs 165 via midhaul communication links 162 (e.g., F1, F1-c, F1-u), and DU 165 may be connected to one or more RUs 170 via fronthaul communication links 168 (e.g., open fronthaul (FH) interface). In some examples, midhaul communication link 162 or fronthaul communication link 168 may be implemented according to an interface (eg, channel) between layers of a protocol stack supported by the respective network entities 105 communicating over those communication links.

[0063] In some wireless communication systems (e.g., wireless communication system 100), infrastructure and spectrum resources for radio access may support wireless backhaul link capabilities to supplement wired backhaul connections, thereby providing an IAB network architecture (e.g., to core network 130). In some cases, in an IAB network, one or more network entities 105 (e.g., IAB nodes 104) may be partially controlled by each other. One or more IAB nodes 104 may be referred to as donor entities or IAB donors. One or more DUs 165 or one or more RUs 170 may be controlled in part by one or more CUs 160 associated with a donor network entity 105 (e.g., a donor base station 140). One or more donor network entities 105 (e.g., IAB donors) may communicate with one or more additional network entities 105 (e.g., IAB nodes 104) via supported access and backhaul links (e.g., backhaul communication links 120). The IAB node 104 may include an IAB mobile terminal (IAB-MT) controlled (e.g., scheduled) by a coupled IAB donor's DU 165. The IAB-MT may include an independent set of antennas for relaying communications with the UE 115, or may share the same antennas of the IAB node 104 (e.g., of the RU 170) for access via the DU 165 of the IAB node 104 (e.g., referred to as a virtual IAB-MT (vIAB-MT)). In some examples, the IAB node 104 may include a DU 165 that supports communication links with additional entities (e.g., IAB node 104, UE 115) within a relay chain or configuration (e.g., downstream) of the access network. In such cases, one or more components of the decomposed RAN architecture (e.g., one or more IAB nodes 104 or components of the IAB node 104) may be configured to operate according to the techniques described herein.

[0064] For example, an access network (AN) or RAN may include an access node (e.g., an IAB donor), communications between an IAB node 104, and one or more UEs 115. An IAB donor may facilitate connectivity between a core network 130 and an AN (e.g., via a wired or wireless connection to the core network 130). That is, an IAB donor may refer to a RAN node having a wired or wireless connection to the core network 130. An IAB donor may include a CU 160 and at least one DU 165 (e.g., and RU 170), in which case the CU 160 may communicate with the core network 130 via an interface (e.g., a backhaul link). The IAB donor and the IAB node 104 may communicate via an F1 interface according to a protocol that defines signaling messages (e.g., an F1 AP protocol). Additionally or alternatively, CU 160 may communicate with the core network via an interface (which may be an example of part of a backhaul link) and may communicate with other CUs 160 (e.g., CUs 160 associated with alternative IAB donors) via an Xn-C interface (which may be an example of part of a backhaul link).

[0065] An IAB node 104 may refer to a RAN node that provides IAB functionality (e.g., access for UE 115, wireless self-backhaul capabilities, etc.). DU 165 may act as a distributed scheduling node toward child nodes associated with IAB node 104, and IAB-MT may act as a scheduled node toward a parent node associated with IAB node 104. That is, an IAB donor may be referred to as a parent node that communicates with one or more child nodes (e.g., an IAB donor may relay transmissions to a UE through one or more other IAB nodes 104). Additionally or alternatively, depending on the relay chain or configuration of the AN, an IAB node 104 may also be referred to as a parent node or child node of other IAB nodes 104. Thus, the IAB-MT entity of IAB node 104 may provide a Uu interface for child IAB node 104 to receive signaling from parent IAB node 104 , and a DU interface (eg, DU 165 ) may provide a Uu interface for parent IAB node 104 to signal to child IAB node 104 or UE 115 .

[0066] For example, the IAB node 104 may be referred to as a parent node that supports communications to a child IAB node, and may be referred to as a child IAB node associated with an IAB donor. The IAB donor may include a CU 160 having a wired or wireless connection (e.g., a backhaul communication link 120) to the core network 130, and may act as a parent node of the IAB node 104. For example, the DU 165 of the IAB donor may relay transmissions to the UE 115 through the IAB node 104, and may directly signal the UE 115 of the transmissions. The CU 160 of the IAB donor may signal the IAB node 104 of the communication link establishment via the F1 interface, and the IAB node 104 may schedule transmissions (e.g., transmissions relayed from the IAB donor to the UE 115) through the DU 165. That is, data may be relayed to and from the IAB node 104 via signaling through the NR Uu interface of the MT to the IAB node 104. Communications with the IAB node 104 may be scheduled by the DU 165 of the IAB donor, and communications with the IAB node 104 may be scheduled by the DU 165 of the IAB node 104 .

[0067] In the case where the techniques described herein are applied to the context of a decomposed RAN architecture, one or more components of the decomposed RAN architecture may be configured to support TRP selection for coherent joint transmission as described herein. For example, some operations described as being performed by UE 115 or network entity 105 (e.g., base station 140) may additionally or alternatively be performed by one or more components of the decomposed RAN architecture (e.g., IAB node 104, DU 165, CU 160, RU 170, RIC 175, SMO 180).

[0068] UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable term, where a "device" may also be referred to as a unit, a station, a terminal, or a client, etc. UE 115 may also include or may be referred to as a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 may include or may be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communication (MTC) device, etc., which may be implemented in various objects such as appliances or vehicles, meters, etc.

[0069] The UE 115 described herein may be capable of communicating with various types of devices, such as other UEs 115, which may sometimes act as relays, as well as network entities 105 and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, etc. Figure 1shown.

[0070] UE 115 and network entity 105 can communicate with each other wirelessly via one or more communication links 125 (e.g., access links) through one or more carriers. The term "carrier" may refer to a set of RF spectrum resources having a physical layer structure defined to support communication link 125. For example, a carrier for communication link 125 may include a portion of an RF spectrum band (e.g., bandwidth portion (BWP)) that operates according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-APro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling for coordinating carrier operations, user data, or other signaling. The wireless communication system 100 may support communication with UE 115 using carrier aggregation or multi-carrier operation. Depending on the carrier aggregation configuration, UE 115 may be configured to have multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation can be used for both frequency division duplex (FDD) and time division duplex (TDD) component carriers. Communication between the network entity 105 and other devices may refer to communication between these devices and any portion (e.g., entity, sub-entity) of the network entity 105. For example, the terms "send," "receive," or "communicate" when referring to the network entity 105 may refer to any portion of the network entity 105 (e.g., base station 140, CU 160, DU 165, RU 170) of the RAN communicating with another device (e.g., directly or via one or more other network entities 105).

[0071] In some examples, such as in a carrier aggregation configuration, a carrier may also have acquisition signaling or control signaling that coordinates the operation of other carriers. A carrier may be associated with a frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute RF Channel Number (EARFCN)) and may be located according to a channel raster for discovery by UE 115. A carrier may operate in a standalone mode, in which case initial acquisition and connection may be made by UE 115 via the carrier, or a carrier may operate in a non-standalone mode, in which case a different carrier (e.g., of the same or different radio access technology) is used to anchor the connection.

[0072] The communication link 125 shown in the wireless communication system 100 may include downlink transmissions (e.g., forward link transmissions) from the network entity 105 to the UE 115 (e.g., in a physical downlink control channel (PDCCH) or a physical downlink shared channel (PDSCH)), uplink transmissions (e.g., return link transmissions) from the UE 115 to the network entity 105 (e.g., in a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH)), or both, as well as other transmission configurations. A carrier may carry downlink communications or uplink communications (e.g., in FDD mode), or may be configured to carry downlink communications and uplink communications (e.g., in TDD mode).

[0073] A carrier may be associated with a particular bandwidth of the RF spectrum, and in some examples, the carrier bandwidth may be referred to as the "system bandwidth" of the carrier or wireless communication system 100. For example, the carrier bandwidth may be one of a set of bandwidths of carriers of a particular radio access technology (e.g., 1.4 megahertz (MHz), 3 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHz, 40 MHz, or 80 MHz). A device of the wireless communication system 100 (e.g., a network entity 105, a UE 115, or both) may have a hardware configuration that supports communication over a particular carrier bandwidth, or may be configurable to support communication over one of the carrier bandwidths in the set of carrier bandwidths. In some examples, the wireless communication system 100 may include a network entity 105 or a UE 115 that supports concurrent communication via carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured to operate over a portion (e.g., a subband, a BWP) or all of a carrier bandwidth.

[0074] The signal waveform transmitted through the carrier may be composed of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system using MCM techniques, a resource element may refer to a symbol period (e.g., the duration of a modulation symbol) and a subcarrier resource, in which case the symbol period and the subcarrier spacing may be inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both), so that the more resource elements a device receives and the higher the order of the modulation scheme, the higher the data rate of the device may be. Wireless communication resources may refer to a combination of RF spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial resources may increase the data rate or data integrity used for communication with UE 115.

[0075] One or more parameter sets for a carrier may be supported, where the parameter set may include subcarrier spacing (Δf) and cyclic prefix. A carrier may be divided into one or more BWPs with the same or different parameter sets. In some examples, a UE 115 may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time, and communications of a UE 115 may be constrained to one or more active BWPs.

[0076] The time interval of the network entity 105 or the UE 115 may be expressed as a multiple of a basic time unit, which may be, for example, a sampling period T s =1 / (Δf max ·N f ) seconds, where Δf max It can represent the maximum supported subcarrier spacing, and N f The maximum supported discrete Fourier transform (DFT) size may be indicated. Time intervals of the communication resources may be organized according to radio frames, each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0077] Each frame may include multiple consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, the frame may be divided into subframes (e.g., in the time domain), and each subframe may be further divided into a certain number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a certain number of symbol periods (e.g., depending on the length of the cyclic prefix appended in front of each symbol period). In some wireless communication systems 100, the time slot may be further divided into multiple micro time slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may include one or more (e.g., N f The duration of a symbol period may depend on the subcarrier spacing or the operating frequency band.

[0078] A subframe, a time slot, a mini-time slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 may be dynamically selected (e.g., in a burst of a shortened TTI (sTTI)).

[0079] Physical channels may be multiplexed on a carrier according to various techniques. Physical control channels and physical data channels may be multiplexed on a downlink carrier using, for example, one or more of a time division multiplexing (TDM) technique, a frequency division multiplexing (FDM) technique, or a hybrid TDM-FDM technique. A control region (e.g., a control resource set (CORESET)) of a physical control channel may be defined by a set of symbol periods and may extend across a system bandwidth of a carrier or a subset of that system bandwidth. One or more control regions (e.g., CORESETs) may be configured for a set of UEs 115. For example, one or more of the UEs 115 may monitor or search a control region for control information according to one or more search space sets, and each search space set may include one or more control channel candidates in one or more aggregation levels arranged in a cascaded manner. The aggregation level of a control channel candidate may refer to the amount of control channel resources (e.g., control channel elements (CCEs)) associated with coded information for a control information format having a given payload size. The search space sets may include a common search space set configured for transmitting control information to multiple UEs 115 , and a UE-specific search space set for transmitting control information to a specific UE 115 .

[0080] The network entity 105 may provide communication coverage via one or more cells (e.g., macro cells, small cells, hot spots, or other types of cells, or any combination thereof). The term "cell" may refer to a logical communication entity used to communicate with the network entity 105 (e.g., via a carrier), and may be associated with an identifier used to distinguish adjacent cells (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID), or other cell identifier). In some examples, a cell may also refer to a coverage area 110 or a portion of a coverage area 110 (e.g., a sector) within which the logical communication entity operates. Depending on various factors such as the capabilities of the network entity 105, such cells may range from smaller areas (e.g., structures, subsets of structures) to larger areas. For example, a cell may be or may include a building, a subset of a building, or an external space between or overlapping coverage areas 110, and the like.

[0081] A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access to UEs 115 that have service subscriptions with a network provider that supports the macro cell. Small cells may be associated with lower power network entities 105 (e.g., lower power base stations 140) than macro cells, and small cells may operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to UEs 115 that have service subscriptions with a network provider, or may provide restricted access to UEs 115 associated with small cells (e.g., UEs 115 in a closed subscriber group (CSG), UEs 115 associated with users in a home or office). A network entity 105 may support one or more cells, and may also use one or more component carriers to support communications on one or more cells.

[0082] In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)) that may provide access to different types of devices.

[0083] In some examples, the network entities 105 (e.g., base stations 140, RUs 170) may be mobile and thus provide communication coverage for mobile coverage areas 110. In some examples, different coverage areas 110 associated with different technologies may overlap, but the different coverage areas 110 may be supported by the same network entity 105. In some other examples, overlapping coverage areas 110 associated with different technologies may be supported by different network entities 105. The wireless communication system 100 may include, for example, a heterogeneous network in which different types of network entities 105 provide coverage for various coverage areas 110 using the same or different radio access technologies.

[0084] Some UEs 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may allow automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technology that allows devices to communicate with each other or with a network entity 105 (e.g., base station 140) without human intervention. In some examples, M2M communication or MTC may include communication from devices with integrated sensors or meters to measure or capture information and relay such information to a central server or application that utilizes the information or presents the information to a person interacting with the application. Some UEs 115 may be designed to collect information or implement automated behavior of machines or other devices. Examples of applications for MTC devices include: smart metering, inventory monitoring, water level monitoring, equipment monitoring, health care monitoring, wildlife monitoring, weather and geographic event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based commercial charging.

[0085] Some UEs 115 may be configured to employ a reduced power consumption mode of operation, such as half-duplex communication (e.g., a mode that supports one-way communication via transmission or reception but does not transmit and receive concurrently). In some examples, half-duplex communication may be performed at a reduced peak rate. Other power saving techniques for UE 115 include entering a power-saving deep sleep mode when not engaged in active communications, operating with limited bandwidth (e.g., according to narrowband communications), or a combination of these techniques. For example, some UEs 115 may be configured to operate using a narrowband protocol type that is associated with a defined portion or range (e.g., a subcarrier or resource block (RB) set) within a carrier, within a guard band of a carrier, or outside a carrier.

[0086] The wireless communication system 100 may be configured to support ultra-reliable communication or low-latency communication or various combinations thereof. For example, the wireless communication system 100 may be configured to support ultra-reliable low-latency communication (URLLC). UE 115 may be designed to support ultra-reliable or low-latency or critical functions. Ultra-reliable communication may include private communication or group communication, and may be supported by one or more services (such as push-to-talk, video, or data). Support for ultra-reliable, low-latency functions may include prioritization of services, and such services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, and ultra-reliable low-latency may be used interchangeably herein.

[0087] In some examples, a UE 115 may be able to communicate directly with other UEs 115 via a device-to-device (D2D) communication link 135 (e.g., according to a peer-to-peer (P2P), D2D, or sidelink protocol). In some examples, one or more UEs 115 in a group that are performing D2D communication may be within a coverage area 110 of a network entity 105 (e.g., a base station 140, a RU 170), and the one or more UEs may support aspects of such D2D communication configured or scheduled by the network entity 105. In some examples, one or more UEs 115 in the group may be outside the coverage area 110 of the network entity 105, or may otherwise be unable or not configured to receive transmissions from the network entity 105. In some examples, a group of UEs 115 communicating via D2D communication may support a one-to-many (1:M) system, in which each UE 115 transmits to each other UE 115 in the group. In some examples, the network entity 105 may facilitate scheduling of resources for D2D communication. In some other examples, D2D communications may be performed between UEs 115 without involving network entity 105 .

[0088] In some systems, the D2D communication link 135 can be an example of a communication channel (such as a sidelink communication channel) between vehicles (e.g., UE 115). In some examples, the vehicles can communicate using vehicle-to-everything (V2X) communication, vehicle-to-vehicle (V2V) communication, or some combination of these items. The vehicles can signal information related to traffic conditions, signal scheduling, weather, safety, emergency situations, or any other information related to the V2X system. In some examples, vehicles in the V2X system can communicate with roadside infrastructure (such as roadside units), or communicate with the network via one or more network nodes (e.g., network entity 105, base station 140, RU 170) using vehicle-to-network (V2N) communication, or both.

[0089] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), which may include at least one control plane entity (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) for managing access and mobility and at least one user plane entity (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)) for routing packets or interconnecting to an external network. The control plane entity may manage non-access layer (NAS) functions, such as mobility, authentication, and bearer management of UE 115 served by a network entity 105 (e.g., a base station 140) associated with the core network 130. User IP packets may be delivered through the user plane entity, which may provide IP address allocation and other functions. The user plane entity may be connected to the IP service 150 of one or more network operators. IP services 150 may include access to the Internet, an intranet, an IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0090] The wireless communication system 100 may operate using one or more frequency bands that may be in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally speaking, the region from 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelength ranges from about one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features (which may be referred to as clusters), but these waves may be sufficient to penetrate structures so that macro cells provide services to UEs 115 located indoors. Transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) than transmission using smaller frequencies and longer wavelengths of the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz.

[0091] The wireless communication system 100 may also operate in a super high frequency (SHF) region using a frequency band from 3 GHz to 30 GHz (also known as a centimeter band) or in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) (also known as a millimeter band). In some examples, the wireless communication system 100 may support millimeter wave (mmW) communications between UE 115 and network entity 105 (e.g., base station 140, RU 170), and the EHF antenna of the corresponding device may be smaller and closer than the UHF antenna. In some examples, this may facilitate the use of antenna arrays within the device. However, there may be even greater atmospheric attenuation and a shorter range for the propagation of EHF transmissions than SHF or UHF transmissions. The technology disclosed herein may be adopted across transmissions using one or more different frequency regions, and the use of frequency bands specified across these frequency regions may vary by country or regulatory agency.

[0092] The wireless communication system 100 may utilize licensed and unlicensed RF spectrum bands. For example, the wireless communication system 100 may use license assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in unlicensed bands such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in an unlicensed RF spectrum band, devices such as the network entity 105 and the UE 115 may employ carrier sensing for conflict detection and avoidance. In some examples, operations in an unlicensed band may be based on a carrier aggregation configuration in conjunction with a component carrier (e.g., LAA) operating in a licensed band. Operations in an unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, and the like.

[0093] The network entity 105 (e.g., base station 140, RU 170) or UE 115 may be equipped with multiple antennas that can be used to employ technologies such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of the network entity 105 or UE 115 may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with the network entity 105 may be located in different geographic locations. The network entity 105 may have an antenna array having a collection of multiple rows and columns of antenna ports that the network entity 105 can use to support beamforming for communications with the UE 115. Similarly, the UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, the antenna panel may support RF beamforming for signals sent via the antenna ports.

[0094] The network entity 105 or UE 115 may use MIMO communication to utilize multipath signal propagation and improve spectral efficiency by sending or receiving multiple signals via different spatial layers. Such a technology may be referred to as spatial multiplexing. The multiple signals may be sent, for example, by a transmitting device via different antennas or different combinations of antennas. Similarly, the multiple signals may be received by a receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry information associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO), in which multiple spatial layers are sent to the same receiving device, and multi-user MIMO (MU-MIMO), in which multiple spatial layers are sent to multiple devices.

[0095] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a network entity 105, a UE 115) to shape or direct an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining signals conveyed via antenna elements of an antenna array so that some signals propagating in a particular direction relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals conveyed via antenna elements may include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to signals carried via antenna elements associated with the device. Adjustments associated with each of these antenna elements may be defined by a set of beamforming weights associated with a particular direction (e.g., relative to the antenna array of the transmitting device or the receiving device or relative to some other direction).

[0096] The network entity 105 or UE 115 may use beam scanning techniques as part of a beamforming operation. For example, the network entity 105 (e.g., base station 140, RU 170) may use multiple antennas or antenna arrays (e.g., antenna panels) to perform beamforming operations for directional communication with UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be sent multiple times by the network entity 105 along different directions. For example, the network entity 105 may send signals according to different sets of beamforming weights associated with different transmission directions. Transmissions along different beam directions may be used to identify (e.g., by a transmitting device, such as network entity 105, or by a receiving device, such as UE 115) beam directions for later transmission or reception by the network entity 105.

[0097] Some signals, such as data signals associated with a particular receiving device, may be sent by a transmitting device (e.g., transmitting network entity 105, transmitting UE 115) along a single beam direction (e.g., a direction associated with a receiving device (such as receiving network entity 105 or receiving UE 115)). In some examples, the beam direction associated with the transmission along the single beam direction may be determined based on signals sent along one or more beam directions. For example, UE 115 may receive one or more of the signals sent by network entity 105 along different directions, and may report to network entity 105 an indication of the signal received by UE 115 with the highest signal quality or other acceptable signal quality.

[0098] In some examples, transmission by a device (e.g., by network entity 105 or UE 115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or beamforming to generate a combined beam for transmission (e.g., from network entity 105 to UE 115). UE 115 may report feedback indicating precoding weights for one or more beam directions, and the feedback may correspond to a configured beam set across a system bandwidth or one or more subbands. Network entity 105 may send a reference signal (e.g., a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS)), which may or may not be precoded. UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-faceted codebook, a linear combination codebook, a port selection codebook). Although these techniques are described with reference to signals sent along one or more directions by a network entity 105 (e.g., base station 140, RU 170), UE 115 may use similar techniques to send signals multiple times along different directions (e.g., to identify a beam direction for subsequent transmission or reception by UE 115), or to send signals along a single direction (e.g., to send data to a receiving device).

[0099] When receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from a receiving device (e.g., network entity 105), the receiving device (e.g., UE 115) may perform receiving operations (e.g., directional listening) according to multiple receiving configurations. For example, the receiving device may perform reception according to multiple receiving directions by: receiving via different antenna subarrays, processing the received signals according to different antenna subarrays, receiving according to different receiving beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or processing the received signals according to different receiving beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as "listening" according to different receiving configurations or receiving directions. In some examples, the receiving device may use a single receiving configuration to receive along a single beam direction (e.g., when receiving a data signal). A single receive configuration may be aligned along a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have the highest signal strength, highest signal-to-noise ratio (SNR), or other acceptable signal quality based on listening according to multiple beam directions).

[0100] The wireless communication system 100 can be a packet-based network that operates according to a layered protocol stack. In the user plane, the communication at the bearer layer or the PDCP layer can be IP-based. The RLC layer can perform packet segmentation and reorganization to communicate on the logical channel. The MAC layer can perform priority processing and multiplexing of logical channels to transport channels. The MAC layer can also use error detection technology, error correction technology, or both to support retransmission at the MAC layer to improve link efficiency. In the control plane, the RRC protocol layer can provide the establishment, configuration and maintenance of the RRC connection of the radio bearer that supports user plane data between the UE 115 and the network entity 105 or the core network 130. At the PHY layer, the transport channel can be mapped to the physical channel.

[0101] The wireless communication system 100 may support multi-TRP communication with the UE 115 to improve the reliability of the communication. For example, when operating in the multi-TRP operation mode, the UE 115 may receive the same downlink data from multiple TRPs, resulting in improved reliability (e.g., a higher chance that the UE 115 receives the data). Multi-TRP transmission may also be referred to as coordinated multi-point (CoMP) transmission, including joint transmission from multiple TRPs to a single UE 115. Multi-TRP transmission or CoMP transmission may include coherent joint transmission and non-coherent joint transmission.

[0102] Figure 2An example of non-coherent joint transmission 200 according to one or more aspects of the present disclosure is illustrated. The non-coherent joint transmission may be based on spatial division multiplexing (SDM), and data may be pre-coded separately at different TRPs. The first TRP 205 may use a pre-decoder V A For data X A pre-decode, and the second TRP 210 can use the pre-decoder V B For data X B Pre-decoding. Pre-decoder V for pre-decoding data sent at TRP The rank of data transmission may be based on the number of transmit antennas at the TRP to be used for data transmission and the rank of data transmission (e.g., V A :4×1,V B :4×2). In addition, the rank of data transmission (e.g., X A :1×1, V B :2×1) sends the data X(RI) to be pre-decoded for the data from TRP TRP ×1) is mapped to different layers. Therefore, the pre-decoded data sent from the first TRP 205 and the second TRP 305 can be given by Formula 1.

[0103]

[0104] Figure 3 An example of coherent joint transmission 300 in accordance with one or more aspects of the present disclosure is illustrated. Coherent joint transmission may refer to transmission including data that is jointly precoded at different TRPs or separately precoded at different TRPs with controlled phases and coefficients.

[0105] In a first example 315 of coherent joint transmission, data may be jointly precoded at different TRPs (eg, data is precoded in a fully joint manner). The first TRP 305 may use a precoder V A The data X is pre-decoded, and the second TRP 310 can use the pre-decoder V B Pre-decode the data X. Pre-decoder V for pre-decoding the data sent at TRP The rank of data transmission may be based on the number of transmit antennas at the TRP to be used for data transmission and the rank of data transmission (e.g., V A :4×2,V B :4×2). In addition, the rank of data transmission (e.g., X A :2×1) will send pre-decoded data X(RI) for the data from the first TRP 305 and the second TRP 310 joint×1) is mapped to different layers. Therefore, the pre-decoded data sent from the first TRP 305 and the second TRP 310 can be given by Formula 2.

[0106]

[0107] In a second example 320 of coherent joint transmission, data may be separately precoded at different TRPs (eg, separate precoders), and the precoders may include in-phase or amplitude coefficients (eg, q A ,q B , or relatively ). Therefore, the pre-decoded data transmission from the first TRP 305 and the second TRP 310 can be given by Formula 3.

[0108]

[0109] In some cases, the phase or amplitude of the precoder may be implicitly included (eg, adapted). In such cases, Equation 3 may be no different than Equation 1 (eg, for non-coherent joint transmission).

[0110] Figure 4 Examples of orientations of different antenna panels 400 for coherent joint transmission according to one or more aspects of the present disclosure are illustrated. One or more TRPs can support coherent joint transmission with backhaul communication and synchronization between TRPs. In one aspect, a co-located TRP or antenna panel (e.g., within a site) can be used for coherent joint transmission. In example 400-a, the TRP can use multiple antenna panels with the same orientation for coherent joint transmission. In example 400-b, the TRP can use multiple antenna panels with different orientations (e.g., between sectors) for coherent joint transmission. On the other hand, a distributed TRP (e.g., between sites) can be used for coherent joint transmission. This aspect is described in example 400-c.

[0111] If the co-located TRP or antenna panel is used for coherent joint transmission, the pre-decoding matrix or pre-decoder used to pre-decode the data can be selected from the joint codebook. Such a pre-decoding matrix or pre-decoder can be given by formula 4.

[0112]

[0113] If distributed TRP is used for coherent joint transmission, the precoding matrix or predecoder used to precode the data can be selected from a separate codebook, and the common amplitude or phase coefficients can be added to the precoding matrix or predecoder. Such a precoding matrix or predecoder can be given by Formula 5.

[0114]

[0115] In some aspects, if the UE 115 is configured to communicate with multiple TRPs, the TRPs may send CSI-RS to the UE 115, and the UE 115 may perform measurements on the CSI-RS to identify an appropriate configuration for communicating with the TRPs. Thus, the UE 115 may monitor the CSI-RS on a CSI-RS resource used for coherent joint transmission (e.g., type IICSI). In an example, the UE 115 may be configured to monitor a single CSI-RS resource for CSI-RS from port groups of different TRPs, or the UE 115 may be configured to monitor multiple CSI-RS resources for CSI-RS from different TRPs. After performing measurements on the CSI-RS, the UE 115 may send a CSI report indicating parameters or configurations used by the TRPs for communicating with the UE 115. For example, the UE 115 may indicate in the CSI report a precoding matrix used for a layer (e.g., ).

[0116] Figure 5 An example of a precoding matrix 500 indicated in a CSI report for multiple layers in accordance with one or more aspects of the present disclosure is illustrated. The UE 115 may indicate a precoding matrix for each of the multiple layers in the CSI report, and the CSI report may support up to a rank of four (i.e., four layers). For each layer, the precoder across the N3 precoding matrix indicator (PMI) subbands may be N t ×N3 matrix W (e.g., ).

[0117] The number of PMI subbands N3 may be determined by the number of channel quality indicator (CQI) subbands and the number of PMI subbands per CQI subband (e.g., R={1,2}). In some cases, the number of CQI subbands may be determined by a higher layer parameter (e.g., csi-ReportingBand), and the number of PMI subbands per CQI subband may also be configured (e.g., by the parameter numberOfPMISubbandsPerCQISubband). For R=1, N3 may be equal to the number of CQI subbands (e.g., with possible values ​​{1,2,…,19}). For R=2, possible values ​​of N3 may be {1,2,…,37}. In some cases, the PMI subband size may be finer (e.g., half) than the CQI subband size, which is better than a PMI subband size equal to the CQI subband size. For edge CQI subbands, the UE 115 may report one PMI if the number of resource blocks is less than or equal to the nominal CQI subband size divided by 2. Alternatively, for edge CQI subbands, the UE 115 may report two PMIs if the number of resource blocks is greater than the CQI subband size divided by 2. For other CQI subbands, the UE 115 may report two PMIs.

[0118] The spatial domain (SD) basis W1 in the matrix (eg, discrete Fourier transform (DFT) basis) may be N t ×2L matrix, where N t W1 may be common to all layers, N t It can be RRC configured (for example, N t =2N1O1N2O2, where O1 and O2 are oversampled), and L can be RRC configured (e.g., L={2,4,6}).

[0119] Frequency Domain (FD) Basis W f (e.g., DFT basis) can be an M×N3 matrix, where M can refer to the number or amount of FD bases, can be layer-specific, and M can be rank-pair specific (e.g., for rank = {1,2}, M1 = M2, and for rank = {3,4}, M3 = M4, where M1 or M3 is RRC configured).

[0120] coefficient It can be a 2L×M matrix and can be layer specific. For each layer, the UE 115 can report up to K0 non-zero coefficients (NZC), where K0 is RRC configured. On all layers, the UE 115 can report up to 2K0 non-zero coefficients. Unreported coefficients can be set to zero, and the UE 115 can perform the following operations before reporting. The coefficients are quantized.

[0121] For layer 1, UE 115 may The NZC of the TRP may be quantized (e.g., layer independent quantization). The NZC may be reported for two different polarizations transmitted from the TRP. The UE 115 may report the index of the strongest coefficient (e.g., NZC), and the strongest coefficient may be used as a reference for the stronger polarization. The stronger polarization may refer to the polarization associated with the strongest coefficient, while the weaker polarization may be another polarization. If the strongest coefficient is one, the UE 115 may not quantize the coefficient. The UE 115 may also report a reference power for the weaker polarization. The UE 115 may quantize the reference power with four bits from 0 dB in steps of -1.5 dB (in power). The UE 115 may also report the differential amplitude of each coefficient. The UE 115 may quantize the differential amplitude with three bits from 0 dB in steps of -3 dB (in power). The UE 115 may also report the phase quantization of each coefficient. The UE 115 may quantize the phase using a 16-phase shift keying (PSK) alphabet. Formula 6 shows the coefficients An example of a matrix (e.g., for type IICSI quantification of ).

[0122]

[0123] The number of SD basis, FD basis and NZC to be reported by UE 115 can be given by Table 1.

[0124] Table 1: Number of SD bases, FD bases and NZC

[0125]

[0126]

[0127] For the number of space domain bases, L = {2, 4, 6}. For the number of FD bases, and For the number of NZC, UE 115 may receive RRC signaling to configure a combination of L, p1, p3, β (eg, 1 out of 8).

[0128] As the number of TRPs that UE 115 may be configured to communicate with increases, the overhead of CSI reporting also increases (e.g., because UE 115 may report the SD basis, FD basis, and precoding coefficients for each TRP). That is, the CSI reporting overhead may increase with the number of TRPs (e.g., N TRP). However, in some cases, it may be appropriate to enable communication with a large number of TRPs or a large number of ports (e.g., for low frequency bands with distributed TRPs or panels). For example, for a single TRP or panel with, for example, 32 ports, the antenna array size may be too large for practical deployment. Therefore, the wireless communication system 100 can support efficient techniques for supporting communication with multiple TRPs while minimizing CSI reporting overhead.

[0129] In one aspect, the UE 115 and the network entity 105 in the wireless communication system 100 can support TRP selection to remove some TRPs with poor channels that may not be worth selecting. Therefore, the UE 115 can avoid reporting parameters for communicating with these TRPs in the CSI report, and the overhead of the CSI report can be reduced. In addition, if an additional dimension (e.g., TRP hierarchy) is introduced, some basic reporting mechanisms in the wireless communication system 100, including SD or FD basis selection and differential quantization of coefficients, can be enhanced across TRPs.

[0130] Figure 6 An example of a wireless communication system 600 that supports TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is illustrated. The wireless communication system 600 includes a UE 115-a, which may be a reference Figures 1 to 5 The wireless communication system 600 also includes TRP 605-a and TRP 605-b, which may be reference Figures 1 to 5 An example of a TRP or network entity 105 is described. The wireless communication system 600 can implement aspects of the wireless communication system 100. For example, the wireless communication system 600 can support efficient techniques for selecting a TRP for communicating with a UE 115-a to minimize the overhead of CSI reporting.

[0131] TRP 605-a may transmit CSI-RS to UE 115-a on one or more layers, and TRP 605-b may transmit CSI-RS to UE 115-a on one or more layers. UE 115-a may perform measurements on the CSI-RS received from TRP 605-a and TRP 605-b, and UE 115-a may use these measurements to select one or both of TRPs 605 with which to communicate. These measurements may include reference signal received power (RSRP) measurements, received signal strength indicators (RSSI), or signal to interference plus noise ratio (SINR) measurements. In an example, if the measurements performed on the CSI-RS received from the TRP meet a threshold, UE 115-a may select a TRP for coherent joint transmission to UE 115-b. Alternatively, UE 115-a may avoid selecting a TRP for coherent joint transmission to UE 115-b if measurements performed on the CSI-RS received from the TRP fail to meet a threshold.

[0132] The UE 115-a may then indicate the selected TRP in the CSI report. For example, the UE 115-a may indicate the TRP based on measurements made on the CSI-RS.

[0133] In some cases, UE 115-a may select a common set of TRPs for communication on multiple layers (e.g., layer-common selection). That is, UE 115-a may select the same set of TRPs for communication on each of the multiple layers. In some examples, UE 115-a may indicate the selected TRPs in a bitmap, and the size of the bitmap may be equal to the total number of TRPs (e.g., N TRPs) from which UE 115-a is selecting TRPs for communication. TRP ). Each bit position in the bitmap may correspond to a different TRP. A bit value of one in the bitmap may indicate that the corresponding TRP is selected for communication with UE 115-a, and a bit value of zero in the bitmap may indicate that the corresponding TRP is not selected for communication with UE 115-a.

[0134] In other cases, the UE 115-a may select a corresponding set of TRPs to use for communication on each of the multiple layers (e.g., a layer-specific selection or a TRP-specific rank). For different layers, the UE 115-a may indicate the selection of TRPs separately in the CSI report. In some examples, the UE 115-a may indicate the selected TRPs in a bitmap, and the size of the bitmap may be equal to the total number of TRPs (e.g., N ) from which the UE 115-a is selecting the TRP for communication. TRP ) multiplied by the total number of layers (e.g., RI×N TRP). Each bit position in the bitmap may correspond to a layer and a TRP. A bit value of one in the bitmap may indicate that the corresponding TRP is selected for communication with UE 115-a on the corresponding layer, and a bit value of zero in the bitmap may indicate that the corresponding TRP is not selected for communication with UE 115-a on the corresponding layer. Alternatively, for the first layer (e.g., layer #0), UE 115-a may assume that all TRPs may be included or selected. Therefore, an indication of a TRP may not be provided in the CSI report, and the bitmap may have a size of (RI-1)×N TRP .

[0135] exist Figure 6 In the example of , UE 115-a may select TRP 605-a for communication on a first layer 620 and a second layer 625, and UE 115-a may select TRP 605-b for communication on the first layer 620. The CSI-RS from the first TRP 605-a on the first layer 620 may be reflected from cluster 610-a to UE 115-a and may avoid obstacle 615-a. The CSI-RS from the first TRP 605-a on the second layer 625 may be reflected from cluster 610-b to UE 115-a and may avoid obstacle 615-a. The CSI-RS from the second TRP 605-b on the first layer 620 may be reflected from cluster 610-b to UE 115-a and may avoid obstacle 615-b. Thus, measurements of these CSI-RS may satisfy a threshold, and the UE 115-a may select a first TRP 605-a based on these measurements for communication on the first layer 620 and the second layer 625, and the UE 115-a may select a second TRP based on these measurements for communication on the first layer 620. Table 2 illustrates an example of TRP selection.

[0136] Table 2: Layer-specific TRP selection

[0137] TRP#0 TRP#1 Layer #0 Select (1) Select (1) Layer #1 Select (1) Not selected (0)

[0138] In some cases, UE 115-a may be configured to include a layer-common TRP selection in the CSI report or to include a layer-specific TRP selection in the CSI report. If UE 115-a is configured to include a layer-specific TRP selection in the CSI report, the number of selected SD or FD bases (e.g., the size of the matrix E1 or W) included in the CSI report may be greater than or equal to 1. f ) can vary from tier to tier (e.g., increasing with the total number of TRPs selected).

[0139] In addition to including TRP selection in the CSI report, UE 115-a may also include SD basis selection and FD basis selection across layers (e.g., layers x1, x2, ...) for the same TRPy (e.g., for each TRP).

[0140] In some cases, UE 115-a may include the SD-based layer common selection in the CSI report for the same TRP. For example, UE 115-a may report the same SD-based layer common selection for layers (x1, x2, ...) containing TRP y. matrix (e.g., while still allowing further SD basis selection through NZC selection). In other cases, the UE 115-a may include a layer-specific selection of SD basis in the CSI report for the same TRP. In one example, for the number of SD basis to be selected (e.g., 2L), the UE 115-a may include a constant number of SD basis for all TRPs (e.g., a constant L for all TRPs) in the CSI report. In another example, the UE 115-a may include a TRP-specific number of SD basis (e.g., a TRP-specific L) in the CSI report. In this example, the UE 115-a may be configured with the total number of SD basis to be included in the CSI report, and the UE 115-a may indicate the selected number of SD basis for each TRP in the CSI report.

[0141] Figure 7 Examples of layer-specific selection of an SD basis 700 in accordance with one or more aspects of the present disclosure are illustrated. In a first example 705, a UE 115-a may include a selection of an SD basis in a CSI report of a first TRP 605-a and a second TRP 605-b for a first layer 620. In a second example 710, a UE 115-a may include a selection of an SD basis in a CSI report of a first TRP 605-a for a second layer 625.

[0142] UE 115-a may also include FD basis selection in the CSI report. For FD basis selection across layers (e.g., layers x1, x2, ...), UE 115-a may include layer-specific selection of FD basis in the same TRP. In other cases, for layer x, the number of FD basis (Mx) for UE 115 to select may be determined by the total number of TRPs selected for layer x. For example, the number of FD basis for UE 115 to select may increase (e.g., proportionally or non-proportionally) with the total number of TRPs selected.

[0143] In some cases, in addition to or in lieu of including SD basis selection and FD basis selection across layers for the same TRP y, UE 115-a may include SD basis selection and FD basis selection within layer x across TRPs (e.g., y1, y2, ...).

[0144] For SD base selection across TRPs within layer x, UE 115-a may include a TRP-specific selection of an SD base or a TRP-common selection of an SD base. The TRP-specific selection of an SD base may include a corresponding SD base for each TRP in the TRPs selected by UE 115-a for communication, and the TRP-common selection of an SD base may include a common or same SD base for all TRPs selected by UE 115-a for communication. In some cases, the TRP-specific selection may be suitable for example 400-b or example 400-c, and the TRP-common selection may be suitable for example 400-a (e.g., panels with the same orientation). UE 115-a may be configured to include a TRP-specific selection of an SD base or a TRP-common selection of an SD base in a CSI report (e.g., depending on whether the TRPs available for communication with UE 115-a are distributed or co-located TRPs).

[0145] For FD basis selection across TRPs within layer x, UE 115-a may include a TRP-specific selection of an FD basis or a TRP-common selection of an FD basis. The TRP-specific selection of an FD basis may include a corresponding FD basis for each TRP in the TRPs selected by UE 115-a for communication, and the TRP-common selection of an FD basis may include a common or same FD basis for all TRPs selected by UE 115-a for communication. In some cases, the TRP-specific selection may be suitable for example 400-c (e.g., with separate codebooks) and the TRP-common selection may be suitable for example 400-a or example 400-b (e.g., with a joint codebook) because different TRPs may have nearly the same path delay (e.g., in example 400-a) or delays that extend within the same range (e.g., in example 400-b). UE 115-a may be configured to include a TRP-specific selection of an FD basis or a TRP-common selection of an FD basis in a CSI report.

[0146] In some cases, the UE 115-a may also be configured to include precoding coefficients in the CSI report (e.g., for a joint codebook or a separate codebook used for precoding). The UE 115-a may perform differential coefficient quantization within each layer to minimize the overhead of reporting the precoding coefficients in the CSI report. In addition, the UE 115-a may include an NZC in the CSI report, and if a value is not reported for a coefficient, the network entity 105 may determine that the value of the coefficient is zero. Therefore, the reported precoding coefficients may be referred to as NZCs. In some cases, the UE 115-a may indicate in the CSI report the strongest coefficients across both polarizations and across all TRPs selected for communication.

[0147] In one example, after identifying the strongest coefficient across polarizations and across TRPs, UE 115-a may identify a first polarization associated with the strongest coefficient and a first TRP associated with the strongest coefficient. UE 115-a may then include in the CSI report an NZC for precoding for the first polarization at the first TRP. These NZCs may be referred to as selected NZCs. In addition to the selected NZC, UE 115-a may also include a set of two or more differential amplitudes (e.g., a differential amplitude between the selected NZC and other NZCs for precoding for the second polarization at the first TRP and at other TRPs (e.g., a TRP other than the first TRP selected for communication with UE 115-a). and In addition, UE 115-a may include one or more differential amplitudes (e.g., ). Thus, UE 115-a may include in the CSI report a two-level common differential quantization of the magnitude of the NZC (e.g., across both polarizations). and and across TRP ). In some cases, UE 115-a may include an additional bit in the CSI report for each TRP (e.g., each TRP without a global SCI) that indicates which polarization is stronger at the TRP. Equations 7 and 8 show a two-level common differential quantization of the magnitude of the NZC for two TRPs.

[0148]

[0149]

[0150] In another example, after identifying the strongest coefficient across polarizations and across TRPs, UE 115-a may identify a first polarization associated with the strongest coefficient. UE 115-a may then include in the CSI report for each TRP selected for communication with UE 115-a the NZC for precoding for the first polarization at the first TRP. These NZCs may be referred to as selected NZCs. In addition to the selected NZCs, UE 115-a may also include in the CSI report for each TRP selected for communication with UE 115-a the differential magnitude (e.g., and ). Thus, UE 115-a may include differential amplitudes across both polarizations in the CSI report (e.g., direct differential quantization of the amplitude of the globally strongest coefficient relative to the same polarization across the TRP). For both the two-level common differential quantization of the amplitude of the NZC and the direct differential quantization of the amplitude of the NZC, the values ​​of the differential amplitudes across polarizations (e.g. and ) can be the same or different. Equations 9 and 10 show the direct differential quantization of the magnitude of NZC for two TRPs.

[0151]

[0152] Figure 8 An example of a process flow 800 for supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is illustrated. The process flow 800 includes a UE 115-b, which may be a reference Figures 1 to 7 The process flow 800 also includes a network entity 805, which may be a reference Figures 1 to 7 An example of a TRP or network entity 105 is described. The process flow 800 can implement aspects of the wireless communication system 600. For example, the process flow 800 can support efficient techniques for selecting a TRP for communicating with the UE 115-b to minimize the overhead of CSI reporting.

[0153] In the following description of process flow 800, signaling exchanged between UE 115-b and network entity 805 may be exchanged in an order different from the example order shown, or operations performed by UE 115-b and network entity 805 may be performed in a different order or at a different time. Some operations may also be omitted from process flow 800, and other operations may be added to process flow 800.

[0154] At 810, the network entity 805 may transmit the CSI-RS to the UE 115-b. The network entity 805 may be a TRP that facilitates the coherent joint transmission to the UE 115-b, or the network entity 805 may coordinate the coherent joint transmission from multiple TRPs to the UE 115-b, for example, as described in reference to Figure 3 and Figure 4As shown. UE 115-b may receive CSI-RS from network entity 805 and / or other network entities. That is, UE 115-b may receive CSI-RS from multiple TRPs. At 815, UE 115-b may generate a CSI report including a TRP selection for transmission to network entity 805, and at 820, UE 115-b may send the CSI report to network entity 805. For example, UE 115-b may send a CSI report based on the CSI-RS received from the multiple TRPs, and network entity 805 may receive the CSI report, and the CSI report may indicate a subset of TRPs selected from the multiple TRPs for communication with UE 115-b, such as as described in reference Figure 6 The CSI report may also indicate additional information of the selected subset of TRPs, such as reference Figure 5 shown.

[0155] In some cases, UE 115-b may include in the CSI report a bitmap indicating a subset of TRPs used for communicating with UE 115-b. The size of the bitmap may be proportional to the amount of multiple TRPs from which the subset of TRPs is selected. In some cases, the size of the bitmap may be equal to the amount of multiple TRPs from which the subset of TRPs is selected. In some cases, the bitmap may indicate a common subset of TRPs used for communicating with UE 115-b on multiple layers. In other cases, the bitmap may indicate a corresponding subset of TRPs used for communicating with UE 115-b on each layer in the multiple layers. In some cases, the network entity 805 may send a configured indication, and UE 115-b may receive the indication, which is used to indicate in the bitmap a common subset of TRPs used for communicating with UE 115-b on a first set of layers or a corresponding subset of TRPs used for communicating with UE 115-b on each layer in a second set of layers.

[0156] In some cases, UE 115-b may include in the CSI report a common selection of the SD basis for each TRP in a subset of TRPs for communicating with UE 115-b on multiple layers. In other cases, UE 115-b may include in the CSI report a respective selection of the SD basis for each TRP in a subset of TRPs for communicating with UE 115-b on each of the multiple layers, as described with reference to FIG. Figure 7As shown. In some cases, the amount of SD basis indicated in the CSI report may be constant for each TRP in a subset of TRPs. In some cases, the amount of SD basis indicated in the CSI report for a TRP in a subset of TRPs may be based on the TRP. In some cases, the network entity 805 may send an indication of a configuration for the total amount of SD basis indicated in the CSI report for UE 115-b, and UE 115-b may receive the indication. In such cases, UE 115-b may indicate in the CSI report the amount of SD basis included in the CSI report for each TRP in a subset of TRPs. In some cases, UE 115-b may include in the CSI report for each layer of a plurality of layers a common selection of the SD basis for each TRP in a subset of TRPs for communication with UE 115-b.

[0157] In some cases, UE 115-b may include in the CSI report a selected NZC for precoding for a first polarization at a first TRP in a subset of TRPs, e.g., as described in reference Figure 5 As shown. The first polarization may be stronger than the second polarization at the first TRP. UE 115-b may also include in the CSI report the first two or more differential amplitudes between the selected NZC and the coefficients used for precoding the second polarization at each TRP in the subset of TRPs. UE 115-b may also include in the CSI report a second one or more differential amplitudes between the selected NZC and the coefficients used for precoding at each TRP in the subset of TRPs other than the first TRP. UE 115-b may also include in the CSI report an indication of whether the first polarization or the second polarization is stronger for each TRP in the subset of TRPs. In some cases, UE 115-b may include in the CSI report for each TRP in the subset of TRPs the selected NZC for precoding the first polarization at the TRP. UE115-b may also include in the CSI report for each TRP the first two or more differential amplitudes between the selected NZC and the coefficients used for precoding the second polarization at each TRP.

[0158] At 825, the network entity 805 may identify parameters for precoding data sent to the UE 115-b based on the CSI report, e.g., as described with reference to Figure 5As shown. For example, the network entity 805 may identify a predecoder for precoding data transmission to UE 115-b based on the SD basis, FD basis, and NZC included in the CSI report. The network entity 805 may then use the predecoder to precode the data for transmission to UE 115-b, and at 830, the network entity 805 may send the data to UE 115-b. For example, the network entity 805 may send at least one of multiple transmissions forming a coherent joint transmission to UE 115-b. The phases and amplitudes of the multiple transmissions forming the coherent joint transmission may be controlled and coordinated by the TRPs participating in the coherent joint transmission. Alternatively, the network entity 805 may coordinate the coherent joint transmission of data to UE 115-b. In any case, UE 115-b may receive coherent joint transmissions from multiple TRPs.

[0159] Fig. 9 A block diagram 900 of a device 905 supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown. The device 905 can be an example of aspects of the UE 115 as described herein. The device 905 may include a receiver 910, a transmitter 915, and a communication manager 920. The device 905 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0160] The receiver 910 may provide means for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels related to TRP selection for coherent joint transmission, data channels, information channels). The information may be communicated to other components of the device 905. The receiver 910 may utilize a single antenna or a collection of multiple antennas.

[0161] The transmitter 915 may provide means for transmitting signals generated by other components of the device 905. For example, the transmitter 915 may transmit information associated with various information channels (e.g., control channels related to TRP selection for coherent joint transmission, data channels, information channels), such as packets, user data, control information, or any combination thereof. In some examples, the transmitter 915 may be co-located with the receiver 910 in a transceiver module. The transmitter 915 may utilize a single antenna or a collection of multiple antennas.

[0162] The communication manager 920, the receiver 910, the transmitter 915, or various combinations thereof, or various components thereof, may be examples of means for performing various aspects of TRP selection for coherent joint transmission as described herein. For example, the communication manager 920, the receiver 910, the transmitter 915, or various combinations thereof, or components thereof, may support methods for performing one or more of the functions described herein.

[0163] In some examples, the communication manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be implemented in hardware (e.g., in a communication management circuit). The hardware may include a processor, a digital signal processor (DSP), a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a microcontroller, discrete gate or transistor logic, discrete hardware components, or any combination thereof that is configured to or otherwise supports means for performing the functions described in the present disclosure. In some examples, the processor and a memory coupled to the processor may be configured to perform one or more of the functions described herein (e.g., by executing instructions stored in the memory by the processor).

[0164] Additionally or alternatively, in some examples, the communication manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be implemented in code executed by a processor (e.g., as communication management software or firmware). If implemented in code executed by a processor, the functionality of the communication manager 920, the receiver 910, the transmitter 915, or various combinations or components thereof may be performed by a general purpose processor (e.g., configured as or otherwise supporting means for performing the functionality described in the present disclosure), a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices.

[0165] In some examples, the communication manager 920 may be configured to perform various operations (e.g., receive, obtain, monitor, output, send) using or otherwise cooperating with the receiver 910, the transmitter 915, or both. For example, the communication manager 920 may receive information from the receiver 910, transmit information to the transmitter 915, or be integrated with the receiver 910, the transmitter 915, or both to obtain information, output information, or perform various other operations as described herein.

[0166] According to examples as disclosed herein, the communication manager 920 may support wireless communications at a UE. For example, the communication manager 920 may be configured to or otherwise support a component for receiving a channel state information reference signal from a set of multiple transmission reception points. The communication manager 920 may be configured to or otherwise support a component for sending a channel state information report based on receiving the channel state information reference signal, the channel state information report indicating a subset of transmission reception points selected from a set of multiple transmission reception points for communicating with the UE. The communication manager 920 may be configured to or otherwise support a component for communicating with a subset of transmission reception points based on sending a channel state information report.

[0167] By including or configuring a communication manager 920 according to examples as described herein, a device 905 (e.g., a processor controlling or otherwise coupled to a receiver 910, a transmitter 915, a communication manager 920, or a combination thereof) may support techniques for reducing processing, reducing power consumption, and more efficiently utilizing communication resources. In particular, because the device 905 may select a subset of TRPs with which to communicate from a set of TRPs, the device 905 may send parameters for communicating with the subset of TRPs in a CSI report, and the device 905 may avoid sending some parameters for other TRPs in the set of TRPs. As a result, the device 905 may expend less power and processing to generate a CSI report (e.g., resulting in reduced processing and power consumption), and the device 905 may use fewer resources to send the CSI report (e.g., resulting in more efficient utilization of communication resources).

[0168] Fig.10 A block diagram 1000 of a device 1005 supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown. The device 1005 can be an example of aspects of the device 905 or UE 115 as described herein. The device 1005 may include a receiver 1010, a transmitter 1015, and a communication manager 1020. The device 1005 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0169] The receiver 1010 may provide means for receiving information (such as packets, user data, control information, or any combination thereof) associated with various information channels (e.g., control channels related to TRP selection for coherent joint transmission, data channels, information channels). The information may be communicated to other components of the device 1005. The receiver 1010 may utilize a single antenna or a collection of multiple antennas.

[0170] The transmitter 1015 may provide means for transmitting signals generated by other components of the device 1005. For example, the transmitter 1015 may transmit information associated with various information channels (e.g., control channels related to TRP selection for coherent joint transmission, data channels, information channels), such as packets, user data, control information, or any combination thereof. In some examples, the transmitter 1015 may be co-located with the receiver 1010 in a transceiver module. The transmitter 1015 may utilize a single antenna or a collection of multiple antennas.

[0171] Device 1005 or its various components may be examples of components for performing various aspects of TRP selection for coherent joint transmission as described herein. For example, communication manager 1020 may include CSI-RS manager 1025, CSI report manager 1030, TRP manager 1035, or any combination thereof. Communication manager 1020 may be an example of various aspects of communication manager 920 as described herein. In some examples, communication manager 1020 or its various components may be configured to use or otherwise cooperate with receiver 1010, transmitter 1015, or both to perform various operations (e.g., receive, obtain, monitor, output, send). For example, communication manager 1020 may receive information from receiver 1010, transmit information to transmitter 1015, or integrate with receiver 1010, transmitter 1015, or both to obtain information, output information, or perform various other operations as described herein.

[0172] According to examples as disclosed herein, the communication manager 1020 may support wireless communications at a UE. The CSI-RS manager 1025 may be configured to or otherwise support a component for receiving a channel state information reference signal from a set of multiple transmission reception points. The CSI report manager 1030 may be configured to or otherwise support a component for sending a channel state information report based on receiving a channel state information reference signal, the channel state information report indicating a subset of transmission reception points selected from a set of multiple transmission reception points for communicating with the UE. The TRP manager 1035 may be configured to or otherwise support a component for communicating with a subset of transmission reception points based on sending a channel state information report.

[0173] Fig.11 A block diagram 1100 of a communication manager 1120 supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown. The communication manager 1120 may be an example of aspects of the communication manager 920, the communication manager 1020, or both as described herein. The communication manager 1120 or its various components may be examples of components for performing various aspects of TRP selection for coherent joint transmission as described herein. For example, the communication manager 1120 may include a CSI-RS manager 1125, a CSI report manager 1130, a TRP manager 1135, a TRP selector 1140, an SD base manager 1145, an FD base manager 1150, a pre-decoding coefficient manager 1155, or any combination thereof. Each of these components may communicate directly or indirectly with each other (e.g., via one or more buses).

[0174] According to examples as disclosed herein, the communication manager 1120 may support wireless communications at a UE. The CSI-RS manager 1125 may be configured to or otherwise support a component for receiving a channel state information reference signal from a set of multiple transmission reception points. The CSI report manager 1130 may be configured to or otherwise support a component for sending a channel state information report based on receiving a channel state information reference signal, the channel state information report indicating a subset of transmission reception points selected from a set of multiple transmission reception points for communicating with the UE. The TRP manager 1135 may be configured to or otherwise support a component for communicating with a subset of transmission reception points based on sending a channel state information report.

[0175] In some examples, TRP selector 1140 may be configured to or otherwise support components for sending a bitmap in a channel state information report indicating a subset of transmit reception points used to communicate with the UE, where the size of the bitmap is proportional to the size of the set of multiple transmit reception points.

[0176] In some examples, the bitmap indicates a common subset of transmit / receive points used to communicate with the UE over a set of multiple layers.

[0177] In some examples, the bitmap indicates a respective subset of transmit / receive points for communicating with the UE on each layer in a set of multiple layers.

[0178] In some examples, the CSI reporting manager 1130 may be configured to or otherwise support a component for receiving an indication of a configuration that indicates in a bitmap a common subset of transmit-receive points for communicating with the UE on a first set of multiple layers, or a corresponding subset of transmit-receive points for communicating with the UE on each layer in a second set of multiple layers.

[0179] In some examples, SD base manager 1145 may be configured to or otherwise support components for sending a common selection of a spatial domain basis for each transmit reception point in a subset of transmit reception points in a channel state information report for communicating with the UE over a set of multiple layers.

[0180] In some examples, SD base manager 1145 may be configured to or otherwise support components for sending in a channel state information report a corresponding selection of a spatial domain basis for each transmit reception point in a subset of transmit reception points for communicating with the UE on each layer in a set of multiple layers.

[0181] In some examples, the amount of spatial domain basis indicated in the channel state information report is constant for each transmit-receive point in the subset of transmit-receive points.

[0182] In some examples, the spatial domain basis quantity for the transmission reception points in the subset of transmission reception points indicated in the channel state information report is based on the transmission reception points.

[0183] In some examples, CSI reporting manager 1130 may be configured or otherwise support means for receiving an indication of a configuration of an amount of a spatial domain basis to be indicated in a channel state information report. In some examples, SD basis manager 1145 may be configured or otherwise support means for sending in a channel state information report an amount of a spatial domain basis for each transmission reception point in a subset of transmission reception points to be included in the channel state information report.

[0184] In some examples, FD basis manager 1150 may be configured to or otherwise support components for transmitting in a channel state information report a corresponding number of selected frequency domain basis for each layer in a set of multiple layers based on the number of transmit receive points selected for communicating with the UE on the layer.

[0185] In some examples, SD base manager 1145 may be configured to or otherwise support components for sending a common selection of a spatial domain basis for each transmit reception point in a subset of transmit reception points in a channel state information report for each layer in a set of multiple layers for communicating with the UE.

[0186] In some examples, the precoding coefficient manager 1155 may be configured to or otherwise support means for sending in a channel state information report a selected non-zero coefficient for precoding for a first polarization at a first transmission reception point in a subset of transmission reception points, wherein the first polarization is stronger than a second polarization at the first transmission reception point. In some examples, the precoding coefficient manager 1155 may be configured to or otherwise support means for sending in a channel state information report a first two or more differential amplitudes between the selected non-zero coefficient and the coefficient for precoding for the second polarization at each transmission reception point in the subset of transmission reception points. In some examples, the precoding coefficient manager 1155 may be configured to or otherwise support means for sending in a channel state information report a second one or more differential amplitudes between the selected non-zero coefficient and the coefficient for precoding at each transmission reception point in the subset of transmission reception points other than the first transmission reception point.

[0187] In some examples, the precoding coefficient manager 1155 may be configured to or otherwise support means for sending in a channel state information report an indication of whether the first polarization or the second polarization is stronger for each transmit reception point in a subset of transmit reception points.

[0188] In some examples, the precoding coefficient manager 1155 may be configured to or otherwise support means for sending, in a channel state information report for a first transmission reception point in the subset of transmission reception points, selected non-zero coefficients for precoding at the first transmission reception point for the first polarization. In some examples, the precoding coefficient manager 1155 may be configured to or otherwise support means for sending, in a channel state information report for the first transmission reception point, one or more differential magnitudes between the selected non-zero coefficients and the coefficients for precoding at the first transmission reception point for the second polarization.

[0189] In some examples, to support communications with a subset of transmitting reception points, the TRP manager 1135 may be configured to or otherwise support components for receiving coherent joint transmissions from the subset of transmitting reception points, wherein the phases of a set of multiple transmissions forming the coherent joint transmission are controlled and coordinated by the subset of transmitting reception points.

[0190] Fig.12 A diagram of a system 1200 including a device 1205 supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown. The device 1205 may be an example of a device 905, a device 1005, or a UE 115 as described herein, or include components thereof. The device 1205 may communicate (e.g., wirelessly) with one or more network entities 105, one or more UEs 115, or any combination thereof. The device 1205 may include components for two-way voice and data communications, including components for sending and receiving communications, such as a communication manager 1220, an input / output (I / O) controller 1210, a transceiver 1215, an antenna 1225, a memory 1230, a code 1235, and a processor 1240. These components may be electronically communicated or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus 1245).

[0191] I / O controller 1210 can manage input and output signals for device 1205. I / O controller 1210 can also manage peripheral devices that are not integrated into device 1205. In some cases, I / O controller 1210 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 1210 can utilize an operating system such as or another known operating system. Additionally or alternatively, I / O controller 1210 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 1210 may be implemented as part of a processor such as processor 1240. In some cases, a user may interact with device 1205 via I / O controller 1210 or via hardware components controlled by I / O controller 1210.

[0192] In some cases, the device 1205 may include a single antenna 1225. However, in some other cases, the device 1205 may have more than one antenna 1225, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 1215 may communicate bidirectionally via one or more antennas 1225, a wired or wireless link, as described herein. For example, the transceiver 1215 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1215 may also include a modem for: modulating packets; providing the modulated packets to one or more antennas 1225 for transmission; and demodulating packets received from one or more antennas 1225. The transceiver 1215 or the transceiver 1215 and one or more antennas 1225 may be examples of transmitters 915, transmitters 1015, receivers 910, receivers 1010, or any combination thereof or components thereof as described herein.

[0193] The memory 1230 may include random access memory (RAM) and read-only memory (ROM). The memory 1230 may store computer-readable, computer-executable code 1235 including instructions that, when executed by the processor 1240, cause the device 1205 to perform various functions described herein. The code 1235 may be stored in a non-transitory computer-readable medium such as a system memory or another type of memory. In some cases, the code 1235 may not be directly executable by the processor 1240, but may (for example, when compiled and executed) cause the computer to perform the functions described herein. In some cases, the memory 1230 may also include, among other things, a basic I / O system (BIOS) that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0194] Processor 1240 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor 1240 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into processor 1240. Processor 1240 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1230) so that device 1205 performs various functions (e.g., functions or tasks supporting TRP selection for coherent joint transmission). For example, device 1205 or a component of device 1205 may include processor 1240 and memory 1230 coupled to or coupled to processor 1240, and processor 1240 and memory 1230 are configured to perform the various functions described herein.

[0195] According to examples as disclosed herein, the communication manager 1220 may support wireless communications at the UE. For example, the communication manager 1220 may be configured to or otherwise support a component for receiving a channel state information reference signal from a set of multiple transmission reception points. The communication manager 1220 may be configured to or otherwise support a component for sending a channel state information report based on receiving the channel state information reference signal, the channel state information report indicating a subset of transmission reception points selected from the set of multiple transmission reception points for communicating with the UE. The communication manager 1220 may be configured to or otherwise support a component for communicating with a subset of transmission reception points based on sending the channel state information report.

[0196] By including or configuring a communication manager 1220 according to examples as described herein, the device 1205 can support techniques for, for example, reducing processing, reducing power consumption, and more efficiently utilizing communication resources. In particular, because the device 1205 can select a subset of TRPs to communicate with from a set of TRPs, the device 1205 can send parameters for communicating with the subset of TRPs in a CSI report, and the device 1205 can avoid sending some parameters for other TRPs in the set of TRPs. Therefore, the device 1205 can expend less power and processing to generate CSI reports (e.g., resulting in reduced processing and power consumption), and the device 1205 can use fewer resources to send CSI reports (e.g., resulting in more efficient utilization of communication resources).

[0197] In some examples, the communication manager 1220 may be configured to perform various operations (e.g., receive, monitor, transmit) using or otherwise cooperating with the transceiver 1215, one or more antennas 1225, or any combination thereof. For example, the communication manager 1220 may be configured to receive or transmit messages or other signaling as described herein via the transceiver 1215. Although the communication manager 1220 is shown as a separate component, in some examples, one or more functions described with reference to the communication manager 1220 may be supported or performed by the processor 1240, the memory 1230, the code 1235, or any combination thereof. For example, the code 1235 may include instructions that are executable by the processor 1240 to cause the device 1205 to perform various aspects of TRP selection for coherent joint transmission as described herein, or the processor 1240 and the memory 1230 may be otherwise configured to perform or support such operations.

[0198] Fig.13 A block diagram 1300 of a device 1305 supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown. The device 1305 can be an example of aspects of the network entity 105 as described herein. In some examples, the device 1305 can be an example of a TRP as described herein. The device 1305 may include a receiver 1310, a transmitter 1315, and a communication manager 1320. The device 1305 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0199] Receiver 1310 may provide means for obtaining (e.g., receiving, determining, identifying) information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). The information may be communicated to other components of device 1305. In some examples, receiver 1310 may support obtaining information by receiving signals via one or more antennas. Additionally or alternatively, receiver 1310 may support obtaining information by receiving signals via one or more wired (e.g., electrical, optical fiber) interfaces, wireless interfaces, or any combination thereof.

[0200] The transmitter 1315 may provide means for outputting (e.g., transmitting, providing, conveying, transmitting) information generated by other components of the device 1305. For example, the transmitter 1315 may output information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack) (such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units)). In some examples, the transmitter 1315 may support outputting information by sending signals via one or more antennas. Additionally or alternatively, the transmitter 1315 may support outputting information by sending signals via one or more wired (e.g., electrical, optical fiber) interfaces, wireless interfaces, or any combination thereof. In some examples, the transmitter 1315 and the receiver 1310 may be co-located in a transceiver, which may include a modem or be coupled to a modem.

[0201] The communication manager 1320, the receiver 1310, the transmitter 1315, or various combinations thereof, or various components thereof, may be examples of means for performing various aspects of TRP selection for coherent joint transmission as described herein. For example, the communication manager 1320, the receiver 1310, the transmitter 1315, or various combinations thereof, or components thereof, may support methods for performing one or more of the functions described herein.

[0202] In some examples, the communication manager 1320, the receiver 1310, the transmitter 1315, or various combinations or components thereof may be implemented in hardware (e.g., in a communication management circuit). The hardware may include a processor, a DSP, a CPU, an ASIC, an FPGA or other programmable logic device, a microprocessor, discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting means for performing the functions described herein. In some examples, the processor and a memory coupled to the processor may be configured to perform one or more of the functions described herein (e.g., by executing instructions stored in the memory by the processor).

[0203] Additionally or alternatively, in some examples, the communication manager 1320, the receiver 1310, the transmitter 1315, or various combinations or components thereof may be implemented in code executed by a processor (e.g., as communication management software or firmware). If implemented in code executed by a processor, the functionality of the communication manager 1320, the receiver 1310, the transmitter 1315, or various combinations or components thereof may be performed by a general purpose processor (e.g., configured as or otherwise supporting means for performing the functionality described in the present disclosure), a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices.

[0204] In some examples, communication manager 1320 may be configured to perform various operations (e.g., receive, obtain, monitor, output, send) using or otherwise cooperating with receiver 1310, transmitter 1315, or both. For example, communication manager 1320 may receive information from receiver 1310, transmit information to transmitter 1315, or be integrated with receiver 1310, transmitter 1315, or both to obtain information, output information, or perform various other operations as described herein.

[0205] According to examples as disclosed herein, the communication manager 1320 may support wireless communications at a network entity. For example, the communication manager 1320 may be configured to or otherwise support a component for sending a channel state information reference signal. The communication manager 1320 may be configured to or otherwise support a component for receiving a channel state information report based on sending a channel state information reference signal, the channel state information report indicating a subset of transmission reception points selected from a set of multiple transmission reception points for communicating with the UE. The communication manager 1320 may be configured to or otherwise support a component for communicating with the UE based on receiving the channel state information report.

[0206] By including or configuring a communication manager 1320 according to examples as described herein, the device 1305 (e.g., a processor controlling or otherwise coupled to the receiver 1310, the transmitter 1315, the communication manager 1320, or a combination thereof) may support techniques for reducing processing, reducing power consumption, and more efficiently utilizing communication resources. Because the device 1305 may support TRP selection for coherent joint transmission, the UE may avoid communicating with unsuitable TRPs, and the UE may avoid reporting parameters for communicating with these TRPs. Thus, the device 1305 may receive and parse less information in a CSI report from the UE (e.g., resulting in reduced processing and power consumption), and the device 1305 may monitor fewer resources for CSI reports (e.g., resulting in more efficient utilization of communication resources).

[0207] Fig.14 A block diagram 1400 of a device 1405 supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown. The device 1405 can be an example of aspects of the device 1305 or network entity 105 as described herein. The device 1405 may include a receiver 1410, a transmitter 1415, and a communication manager 1420. The device 1405 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0208] Receiver 1410 may provide means for obtaining (e.g., receiving, determining, identifying) information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). The information may be communicated to other components of device 1405. In some examples, receiver 1410 may support obtaining information by receiving signals via one or more antennas. Additionally or alternatively, receiver 1410 may support obtaining information by receiving signals via one or more wired (e.g., electrical, optical fiber) interfaces, wireless interfaces, or any combination thereof.

[0209] The transmitter 1415 may provide means for outputting (e.g., sending, providing, conveying, transmitting) information generated by other components of the device 1405. For example, the transmitter 1415 may output information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack) (such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units)). In some examples, the transmitter 1415 may support outputting information by sending signals via one or more antennas. Additionally or alternatively, the transmitter 1415 may support outputting information by sending signals via one or more wired (e.g., electrical, optical fiber) interfaces, wireless interfaces, or any combination thereof. In some examples, the transmitter 1415 and the receiver 1410 may be co-located in a transceiver, which may include a modem or be coupled to a modem.

[0210] Device 1405 or its various components may be examples of components for performing various aspects of TRP selection for coherent joint transmission as described herein. For example, communication manager 1420 may include CSI-RS manager 1425, CSI report manager 1430, TRP manager 1435, or any combination thereof. Communication manager 1420 may be an example of various aspects of communication manager 1320 as described herein. In some examples, communication manager 1420 or its various components may be configured to use or otherwise cooperate with receiver 1410, transmitter 1415, or both to perform various operations (e.g., receive, obtain, monitor, output, send). For example, communication manager 1420 may receive information from receiver 1410, transmit information to transmitter 1415, or integrate with receiver 1410, transmitter 1415, or both to obtain information, output information, or perform various other operations as described herein.

[0211] According to examples as disclosed herein, the communication manager 1420 may support wireless communications at a network entity. The CSI-RS manager 1425 may be configured to or otherwise support a component for sending a channel state information reference signal. The CSI report manager 1430 may be configured to or otherwise support a component for receiving a channel state information report based on sending a channel state information reference signal, the channel state information report indicating a subset of transmit reception points selected from a set of multiple transmit reception points for communicating with the UE. The TRP manager 1435 may be configured to or otherwise support a component for communicating with the UE based on receiving the channel state information report.

[0212] Fig.15 A block diagram 1500 of a communication manager 1520 supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown. The communication manager 1520 may be an example of aspects of the communication manager 1320, the communication manager 1420, or both as described herein. The communication manager 1520 or its various components may be examples of means for performing various aspects of TRP selection for coherent joint transmission as described herein. For example, the communication manager 1520 may include a CSI-RS manager 1525, a CSI report manager 1530, a TRP manager 1535, an SD base manager 1540, an FD base manager 1545, a pre-coding coefficient manager 1550, or any combination thereof. Each of these components may communicate directly or indirectly with each other (e.g., via one or more buses), which communication may include communication within a protocol layer of a protocol stack, communication associated with a logical channel of a protocol stack (e.g., between protocol layers of a protocol stack, within a device, component, or virtualized component associated with the network entity 105, between devices, components, or virtualized components associated with the network entity 105), or any combination thereof.

[0213] According to examples as disclosed herein, the communication manager 1520 may support wireless communications at a network entity. The CSI-RS manager 1525 may be configured to or otherwise support a component for sending a channel state information reference signal. The CSI report manager 1530 may be configured to or otherwise support a component for receiving a channel state information report based on sending a channel state information reference signal, the channel state information report indicating a subset of transmit reception points selected from a set of multiple transmit reception points for communicating with the UE. The TRP manager 1535 may be configured to or otherwise support a component for communicating with the UE based on receiving the channel state information report.

[0214] In some examples, the TRP manager 1535 may be configured to or otherwise support components for receiving a bitmap in a channel state information report indicating a subset of transmit reception points used to communicate with the UE, where the size of the bitmap is proportional to the size of the set of multiple transmit reception points.

[0215] In some examples, the bitmap indicates a common subset of transmit / receive points used to communicate with the UE over a set of multiple layers.

[0216] In some examples, the bitmap indicates a respective subset of transmit / receive points for communicating with the UE on each layer in a set of multiple layers.

[0217] In some examples, the CSI reporting manager 1530 may be configured to or otherwise support a component for sending a configured indication that indicates in a bitmap a common subset of transmit reception points for communicating with the UE on a first set of multiple layers, or a corresponding subset of transmit reception points for communicating with the UE on each layer in a second set of multiple layers.

[0218] In some examples, SD base manager 1540 may be configured to or otherwise support components for receiving a common selection of a spatial domain basis for each transmit reception point in a subset of transmit reception points in a channel state information report for communicating with the UE over a set of multiple layers.

[0219] In some examples, SD base manager 1540 may be configured to or otherwise support components for receiving in a channel state information report a corresponding selection of a spatial domain basis for each transmit reception point in a subset of transmit reception points for communicating with the UE on each layer in a set of multiple layers.

[0220] In some examples, the amount of spatial domain basis indicated in the channel state information report is constant for each transmit-receive point in the subset of transmit-receive points.

[0221] In some examples, the spatial domain basis quantity for the transmission reception points in the subset of transmission reception points indicated in the channel state information report is based on the transmission reception points.

[0222] In some examples, CSI reporting manager 1530 may be configured or otherwise support means for sending a configured indication of the total amount of spatial domain basis to be indicated in the channel state information report. In some examples, SD basis manager 1540 may be configured or otherwise support means for receiving in the channel state information report the amount of spatial domain basis included in the channel state information report for each transmission reception point in the subset of transmission reception points.

[0223] In some examples, the FD basis manager 1545 may be configured to or otherwise support components for receiving in a channel state information report a corresponding number of selected frequency domain basis for each layer in a set of multiple layers based on the number of transmit receive points selected for communicating with the UE on the layer.

[0224] In some examples, SD base manager 1540 may be configured to or otherwise support components for receiving a common selection of a spatial domain basis for each transmit reception point in a subset of transmit reception points in a channel state information report for each layer in a set of multiple layers for communicating with the UE.

[0225] In some examples, the precoding coefficient manager 1550 may be configured to or otherwise support means for receiving in a channel state information report a selected non-zero coefficient for precoding for a first polarization at a first transmission reception point in a subset of transmission reception points, wherein the first polarization is stronger than a second polarization at the first transmission reception point. In some examples, the precoding coefficient manager 1550 may be configured to or otherwise support means for receiving in a channel state information report a first two or more differential magnitudes between the selected non-zero coefficient and the coefficient for precoding for the second polarization at each transmission reception point in the subset of transmission reception points. In some examples, the precoding coefficient manager 1550 may be configured to or otherwise support means for receiving in a channel state information report a second one or more differential magnitudes between the selected non-zero coefficient and the coefficient for precoding at each transmission reception point in the subset of transmission reception points other than the first transmission reception point.

[0226] In some examples, precoding coefficient manager 1550 may be configured or otherwise support means for receiving in a channel state information report an indication of whether the first polarization or the second polarization is stronger for each transmit reception point in a subset of transmit reception points.

[0227] In some examples, precoding coefficient manager 1550 may be configured to or otherwise support means for receiving, in a channel state information report for a first transmission reception point in the subset of transmission reception points, selected non-zero coefficients for precoding at the first transmission reception point for the first polarization. In some examples, precoding coefficient manager 1550 may be configured to or otherwise support means for receiving, in a channel state information report for the first transmission reception point, one or more differential magnitudes between the selected non-zero coefficients and the coefficients for precoding at the first transmission reception point for the second polarization.

[0228] In some examples, to support communication with a UE, TRP manager 1535 may be configured to or otherwise support components for sending at least one transmission from a set of multiple transmissions forming a coherent joint transmission to the UE, wherein the phases of the set of multiple transmissions forming the coherent joint transmission are controlled and coordinated by a subset of the transmit receive points.

[0229] Fig.16 A diagram of a system 1600 including a device 1605 supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure is shown. Device 1605 may be an example of device 1305, device 1405, or network entity 105 as described herein, or include components thereof. Device 1605 may communicate with one or more network entities 105, one or more UEs 115, or any combination thereof, which communication may include communication through one or more wired interfaces, through one or more wireless interfaces, or any combination thereof. Device 1605 may include components that support output and acquisition of communications, such as a communication manager 1620, a transceiver 1610, an antenna 1615, a memory 1625, a code 1630, and a processor 1635. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., bus 1640).

[0230] The transceiver 1610 may support bidirectional communication via a wired link, a wireless link, or both, as described herein. In some examples, the transceiver 1610 may include a wired transceiver and may communicate bidirectionally with another wired transceiver. Additionally or alternatively, in some examples, the transceiver 1610 may include a wireless transceiver and may communicate bidirectionally with another wireless transceiver. In some examples, the device 1605 may include one or more antennas 1615 that may be capable of (e.g., concurrently) sending or receiving wireless transmissions. The transceiver 1610 may also include a modem for modulating a signal, providing the modulated signal for transmission (e.g., through one or more antennas 1615, through a wired transmitter), receiving the modulated signal (e.g., from one or more antennas 1615, from a wired receiver), and demodulating the signal. The transceiver 1610 or the transceiver 1610 and one or more antennas 1615 or a wired interface (where applicable) may be an example of a transmitter 1315, a transmitter 1415, a receiver 1310, a receiver 1410, or any combination thereof or any component thereof as described herein. In some examples, the transceiver may be operable to support communication via one or more communication links (e.g., communication link 125, backhaul communication link 120, midhaul communication link 162, fronthaul communication link 168).

[0231] Memory 1625 may include RAM and ROM. Memory 1625 may store computer-readable, computer-executable code 1630 including instructions that, when executed by processor 1635, cause device 1605 to perform various functions described herein. Code 1630 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, code 1630 may not be directly executable by processor 1635, but may (e.g., when compiled and executed) cause a computer to perform the functions described herein. In some cases, memory 1625 may also include, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0232] Processor 1635 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA, a microcontroller, a programmable logic device, a discrete gate or transistor logic element, a discrete hardware component, or any combination thereof). In some cases, processor 1635 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into processor 1635. Processor 1635 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1625) so that device 1605 performs various functions (e.g., functions or tasks supporting TRP selection for coherent joint transmission). For example, device 1605 or a component of device 1605 may include processor 1635 and memory 1625 coupled to processor 1635, and processor 1635 and memory 1625 are configured to perform the various functions described herein. Processor 1635 can be an example of a cloud computing platform (e.g., one or more physical nodes and supporting software such as an operating system, virtual machine, or container instance) that can host functionality for performing functions of device 1605 (e.g., by executing code 1630).

[0233] In some examples, bus 1640 may support communications of protocol layers (e.g., within a protocol layer) of a protocol stack. In some examples, bus 1640 may support communications associated with logical channels of a protocol stack (e.g., between protocol layers of a protocol stack), which may include communications performed within components of device 1605, or communications performed between different components of device 1605 that may be co-located or located in different locations (e.g., where device 1605 may refer to a system in which one or more of communication manager 1620, transceiver 1610, memory 1625, code 1630, and processor 1635 may be located in one of these different components or divided between different components).

[0234] In some examples, communication manager 1620 may manage aspects of communications with core network 130 (e.g., via one or more wired or wireless backhaul links). For example, communication manager 1620 may manage delivery of data communications for client devices such as one or more UEs 115. In some examples, communication manager 1620 may manage communications with other network entities 105 and may include a controller or scheduler for controlling communications with UE 115 in coordination with other network entities 105. In some examples, communication manager 1620 may support an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between network entities 105.

[0235] According to examples as disclosed herein, the communication manager 1620 may support wireless communications at a network entity. For example, the communication manager 1620 may be configured to or otherwise support a component for sending a channel state information reference signal. The communication manager 1620 may be configured to or otherwise support a component for receiving a channel state information report based on sending a channel state information reference signal, the channel state information report indicating a subset of transmission reception points selected from a set of multiple transmission reception points for communicating with the UE. The communication manager 1620 may be configured to or otherwise support a component for communicating with the UE based on receiving the channel state information report.

[0236] By including or configuring a communication manager 1620 according to an example as described herein, the device 1605 can support techniques for, for example, reducing processing, reducing power consumption, and more efficiently utilizing communication resources. Because the device 1605 can support TRP selection for coherent joint transmission, the UE can avoid communicating with unsuitable TRPs, and the UE can avoid reporting parameters for communicating with these TRPs. Therefore, the device 1605 can receive and parse less information in the CSI report from the UE (e.g., resulting in reduced processing and power consumption), and the device 1605 can monitor fewer resources for CSI reports (e.g., resulting in more efficient utilization of communication resources).

[0237] In some examples, the communication manager 1620 may be configured to perform various operations (e.g., receive, obtain, monitor, output, transmit) using or otherwise cooperating with the transceiver 1610, one or more antennas 1615 (e.g., where applicable), or any combination thereof. For example, the communication manager 1620 may be configured to receive or transmit messages or other signaling as described herein via the transceiver 1610. Although the communication manager 1620 is illustrated as a separate component, in some examples, one or more functions described with reference to the communication manager 1620 may be supported or performed by the processor 1635, the memory 1625, the code 1630, the transceiver 1610, or any combination thereof. For example, the code 1630 may include instructions that are executable by the processor 1635 to cause the device 1605 to perform various aspects of TRP selection for coherent joint transmission as described herein, or the processor 1635 and the memory 1625 may be otherwise configured to perform or support such operations.

[0238] Fig.17 1 is a flowchart illustrating a method 1700 for supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure. The operations of the method 1700 may be implemented by a UE or a component thereof as described herein. For example, the operations of the method 1700 may be implemented by a UE or a component thereof as described in reference to Figures 1 to 12 The UE 115 described above may be used to perform. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the described functions.

[0239] At 1705, the method may include receiving a channel state information reference signal from a set of multiple transmission reception points, such as a reference signal Figure 8 As shown at 810. The operations of 1705 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1705 may be performed as described in reference Fig.11 The CSI-RS manager 1125 is described. Additionally or alternatively, the means for performing 1705 may (but not necessarily) include, for example, an antenna 1225, a transceiver 1215, a communication manager 1220, a memory 1230 (including code 1235), a processor 1240, and / or a bus 1245.

[0240] At 1710, the method may include sending a channel state information report based on receiving a channel state information reference signal, the channel state information report indicating a subset of transmission reception points selected from a set of multiple transmission reception points for communicating with the UE, such as reference Figure 8As shown at 820. The operations of 1710 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1710 may be performed as described in reference Fig.11 The CSI report manager 1130 is executed. Additionally or alternatively, the means for executing 1710 may (but not necessarily) include, for example, an antenna 1225, a transceiver 1215, a communication manager 1220, a memory 1230 (including code 1235), a processor 1240 and / or a bus 1245.

[0241] At 1715, the method may include communicating with a subset of the transmitting reception points based on transmitting a channel state information report, such as described in reference Figure 8 As shown at 830. The operations of 1715 can be performed according to examples disclosed herein. In some examples, aspects of the operations of 1715 can be performed as described in reference Fig.11 The TRP manager 1135 is described. Additionally or alternatively, the means for executing 1715 may (but not necessarily) include, for example, an antenna 1225, a transceiver 1215, a communication manager 1220, a memory 1230 (including code 1235), a processor 1240 and / or a bus 1245.

[0242] Fig.18 1 is a flow chart illustrating a method 1800 for supporting TRP selection for coherent joint transmission according to one or more aspects of the present disclosure. The operations of the method 1800 may be implemented by a network entity or a component thereof as described herein. For example, the operations of the method 1800 may be implemented by a network entity or a component thereof as described herein. Figures 1 to 8 as well as Figures 13 to 16 In some examples, the network entity may execute an instruction set to control the functional elements of the network entity to perform the described functions. Additionally or alternatively, the network entity may use dedicated hardware to perform various aspects of the described functions.

[0243] At 1805, the method may include sending a channel state information reference signal, such as a reference Figure 8 As shown at 810. The operations of 1805 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1805 may be performed as described in reference Fig.15 The CSI-RS manager 1525 is used to perform. Additionally or alternatively, the means for performing 1805 may (but not necessarily) include, for example, an antenna 1615, a transceiver 1610, a communication manager 1620, a memory 1625 (including code 1630), a processor 1635 and / or a bus 1640.

[0244] At 1810, the method may include receiving a channel state information report based on transmitting a channel state information reference signal, the channel state information report indicating a subset of transmit reception points selected from a set of multiple transmit reception points for communicating with the UE, such as reference Figure 8 As shown at 820. The operations of 1810 may be performed according to examples disclosed herein. In some examples, aspects of the operations of 1810 may be performed as described in reference Fig.15 The CSI report manager 1530 is executed. Additionally or alternatively, the means for executing 1810 may (but not necessarily) include, for example, an antenna 1615, a transceiver 1610, a communication manager 1620, a memory 1625 (including code 1630), a processor 1635 and / or a bus 1640.

[0245] At 1815, the method may include communicating with the UE based on receiving the channel state information report, such as described in reference Figure 8 As shown at 830. The operations of 1815 can be performed according to examples disclosed herein. In some examples, aspects of the operations of 1815 can be performed as described in reference Fig.15 The TRP manager 1535 is used to perform. Additionally or alternatively, the means for performing 1815 may (but not necessarily) include, for example, an antenna 1615, a transceiver 1610, a communication manager 1620, a memory 1625 (including code 1630), a processor 1635 and / or a bus 1640.

[0246] The following provides an overview of various aspects of the disclosure:

[0247] Aspect 1: A method for performing wireless communications at a UE, the method comprising: receiving a channel state information reference signal from a plurality of transmission receiving points; sending a channel state information report based at least in part on receiving the channel state information reference signal, the channel state information report indicating a subset of transmission receiving points selected from the plurality of transmission receiving points for communicating with the UE; and communicating with the subset of transmission receiving points based at least in part on sending the channel state information report.

[0248] Aspect 2: The method according to Aspect 1 further includes: sending a bitmap indicating a subset of the transmission and reception points used to communicate with the UE in the channel state information report, wherein the size of the bitmap is proportional to the amount of the multiple transmission and reception points.

[0249] Aspect 3: The method according to aspect 2, wherein the bitmap indicates a common subset of transmission and reception points used to communicate with the UE on multiple layers.

[0250] Aspect 4: The method according to any one of aspects 2 to 3, wherein the bitmap indicates a corresponding subset of transmission and reception points used for communicating with the UE on each of a plurality of layers.

[0251] Aspect 5: The method according to any one of Aspects 2 to 4 further includes: receiving a configured indication, wherein the indication is used to indicate in the bitmap a common subset of transmitting and receiving points for communicating with the UE on the first multiple layers, or a corresponding subset of transmitting and receiving points for communicating with the UE on each layer in the second multiple layers.

[0252] Aspect 6: The method according to any one of Aspects 1 to 5 further includes: sending a common selection of a spatial domain basis for each transmitting / receiving point in the subset of transmitting / receiving points in the channel state information report for communicating with the UE on multiple layers.

[0253] Aspect 7: The method according to any one of Aspects 1 to 6 further includes: sending in the channel state information report a corresponding selection of a spatial domain basis for each transmitting / receiving point in the subset of transmitting / receiving points for communicating with the UE on each of multiple layers.

[0254] Aspect 8: The method according to any one of aspects 1 to 7, wherein the amount of the spatial domain basis indicated in the channel state information report is constant for each transmission reception point in the subset of transmission reception points.

[0255] Aspect 9: A method according to any one of aspects 1 to 8, wherein the amount of the spatial domain basis for the transmission reception point in the subset of the transmission reception points indicated in the channel state information report is at least partially based on the transmission reception point.

[0256] Aspect 10: The method according to any one of Aspects 1 to 9 further includes: receiving an indication of a configuration of the total amount of spatial domain basis to be indicated in the channel state information report; and sending in the channel state information report the amount of spatial domain basis included in the channel state information report for each transmitting / receiving point in the subset of transmitting / receiving points.

[0257] Aspect 11: The method according to any one of Aspects 1 to 10 further includes: sending a corresponding number of selected frequency domain bases for each layer of multiple layers in the channel state information report at least in part based on the number of transmitting and receiving points selected for communicating with the UE on the layer.

[0258] Aspect 12: The method according to any one of Aspects 1 to 11 further includes: sending a common selection of a spatial domain basis for each transmitting / receiving point in the subset of transmitting / receiving points in the channel state information report for each layer in multiple layers for communicating with the UE.

[0259] Aspect 13: The method according to any one of Aspects 1 to 12 also includes: sending in the channel state information report a selected non-zero coefficient for precoding a first polarization at a first transmitting and receiving point in a subset of the transmitting and receiving points, wherein the first polarization is stronger than the second polarization at the first transmitting and receiving point; sending in the channel state information report the first two or more differential amplitudes between the selected non-zero coefficient and the coefficient for precoding a second polarization at each transmitting and receiving point in the subset of the transmitting and receiving points; and sending in the channel state information report a second one or more differential amplitudes between the selected non-zero coefficient and the coefficient for precoding at each transmitting and receiving point in the subset of the transmitting and receiving points except the first transmitting and receiving point.

[0260] Aspect 14: The method according to aspect 13 further includes: sending an indication of whether the first polarization or the second polarization is stronger for each transmission and reception point in the subset of transmission and reception points in the channel state information report.

[0261] Aspect 15: The method according to any one of Aspects 1 to 14 further includes: sending selected non-zero coefficients for precoding for a first polarization at a first transmitting and receiving point in the channel state information report for a first transmitting and receiving point in the subset of transmitting and receiving points; and sending one or more differential amplitudes between the selected non-zero coefficients and the coefficients for precoding for a second polarization at the first transmitting and receiving point in the channel state information report for the first transmitting and receiving point.

[0262] Aspect 16: A method according to any one of Aspects 1 to 15, wherein communicating with a subset of the transmitting and receiving points includes: receiving a coherent joint transmission from the subset of the transmitting and receiving points, wherein the phases of multiple transmissions forming the coherent joint transmission are controlled and coordinated by the subset of the transmitting and receiving points.

[0263] Aspect 17: A method for performing wireless communications at a network entity, the method comprising: sending a channel state information reference signal; receiving a channel state information report based at least in part on sending the channel state information reference signal, the channel state information report indicating a subset of transmitting and receiving points selected from a plurality of transmitting and receiving points for communicating with a UE; and communicating with the UE based at least in part on receiving the channel state information report.

[0264] Aspect 18: The method according to Aspect 17 also includes: receiving a bitmap indicating a subset of the transmission and reception points used to communicate with the UE in the channel state information report, wherein the size of the bitmap is proportional to the amount of the multiple transmission and reception points.

[0265] Aspect 19: The method according to aspect 18, wherein the bitmap indicates a common subset of transmission and reception points used to communicate with the UE on multiple layers.

[0266] Aspect 20: The method according to any one of aspects 18 to 19, wherein the bitmap indicates a respective subset of transmission and reception points used for communicating with the UE on each of a plurality of layers.

[0267] Aspect 21: The method according to any one of Aspects 18 to 20 further includes: sending a configuration indication, wherein the indication is used to indicate in the bitmap a common subset of sending and receiving points for communicating with the UE on a first plurality of layers, or a corresponding subset of sending and receiving points for communicating with the UE on each layer in a second plurality of layers.

[0268] Aspect 22: The method according to any one of Aspects 17 to 21 further includes: receiving in the channel state information report a common selection of a spatial domain basis for each transmitting / receiving point in the subset of transmitting / receiving points for communicating with the UE on multiple layers.

[0269] Aspect 23: The method according to any one of Aspects 17 to 22 further includes: receiving in the channel state information report a corresponding selection of a spatial domain basis for each transmitting / receiving point in the subset of transmitting / receiving points for communicating with the UE on each of multiple layers.

[0270] Aspect 24: A method according to any one of aspects 17 to 23, wherein the amount of the spatial domain basis indicated in the channel state information report is constant for each transmission reception point in the subset of transmission reception points.

[0271] Aspect 25: A method according to any one of Aspects 17 to 24, wherein the amount of the spatial domain basis for the transmission reception point in the subset of the transmission reception points indicated in the channel state information report is at least partially based on the transmission reception point.

[0272] Aspect 26: The method according to any one of Aspects 17 to 25 further includes: sending an indication of the configuration of the total amount of spatial domain basis to be indicated in the channel state information report; and receiving in the channel state information report the amount of spatial domain basis included in the channel state information report for each transmitting / receiving point in the subset of the transmitting / receiving points.

[0273] Aspect 27: The method according to any one of Aspects 17 to 26 further includes: receiving a corresponding number of selected frequency domain bases for each of multiple layers in the channel state information report at least in part based on the number of transmitting and receiving points selected for communicating with the UE on the layer.

[0274] Aspect 28: The method according to any one of Aspects 17 to 27 further includes: receiving a common selection of a spatial domain basis for each transmitting / receiving point in the subset of transmitting / receiving points in the channel state information report for each layer in multiple layers for communicating with the UE.

[0275] Aspect 29: The method according to any one of Aspects 17 to 28 further includes: receiving in the channel state information report a selected non-zero coefficient for precoding a first polarization at a first transmitting and receiving point in a subset of the transmitting and receiving points, wherein the first polarization is stronger than the second polarization at the first transmitting and receiving point; receiving in the channel state information report the first two or more differential amplitudes between the selected non-zero coefficient and the coefficient for precoding the second polarization at each transmitting and receiving point in the subset of the transmitting and receiving points; and receiving in the channel state information report a second one or more differential amplitudes between the selected non-zero coefficient and the coefficient for precoding at each transmitting and receiving point in the subset of the transmitting and receiving points except the first transmitting and receiving point.

[0276] Aspect 30: The method according to aspect 29 further comprises: receiving in the channel state information report an indication of whether the first polarization or the second polarization is stronger for each of the subset of the transmission and reception points.

[0277] Aspect 31: The method according to any one of Aspects 17 to 30 further includes: receiving selected non-zero coefficients for precoding a first polarization at a first transmitting and receiving point in the channel state information report for a first transmitting and receiving point in the subset of transmitting and receiving points; and receiving one or more differential amplitudes between the selected non-zero coefficients and the coefficients for precoding a second polarization at the first transmitting and receiving point in the channel state information report for the first transmitting and receiving point.

[0278] Aspect 32: A method according to any one of Aspects 17 to 31, wherein communicating with the UE includes: sending at least one of multiple transmissions forming a coherent joint transmission to the UE, wherein the phases of the multiple transmissions forming the coherent joint transmission are controlled and coordinated by a subset of the transmitting and receiving points.

[0279] Aspect 33: An apparatus for performing wireless communications at a UE, the apparatus comprising: a memory; a transceiver; and at least one processor, the at least one processor being coupled to the memory and the transceiver, the at least one processor being configured to execute a method according to any one of Aspects 1 to 16.

[0280] Aspect 34: An apparatus for wireless communication at a UE, the apparatus comprising at least one means for performing a method according to any one of aspects 1 to 16.

[0281] Aspect 35: A non-transitory computer-readable medium storing a code for wireless communication at a UE, the code comprising instructions executable by a processor to perform a method according to any one of aspects 1 to 16.

[0282] Aspect 36: An apparatus for wireless communication at a network entity, the apparatus comprising: a memory; a transceiver; and at least one processor, the at least one processor being coupled to the memory and the transceiver, the at least one processor being configured to perform a method according to any one of Aspects 17 to 32.

[0283] Aspect 37: An apparatus for wireless communication at a network entity, the apparatus comprising at least one means for performing a method according to any one of aspects 17 to 32.

[0284] Aspect 38: A non-transitory computer-readable medium storing code for wireless communication at a network entity, the code comprising instructions executable by a processor to perform the method according to any one of aspects 17 to 32.

[0285] It should be noted that the methods described herein describe possible implementations, and that the operations and steps may be rearranged or otherwise modified and that other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0286] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein may also be applicable to networks other than LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communication systems, such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0287] The information and signals described herein may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the specification may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0288] The various illustrative blocks and components described in conjunction with the disclosure herein may be implemented or performed with a general purpose processor, DSP, ASIC, CPU, FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0289] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. When implemented in software executed by a processor, the functions may be stored on or sent via a computer-readable medium as one or more instructions or codes. Other examples and specific implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hard wiring, or a combination of any of these items. Features that implement the functions may also be physically located at different locations, including being distributed so that various parts of the functions are implemented at different physical locations.

[0290] Computer-readable medium includes both non-transient computer storage medium and communication medium, and it includes any medium that promotes the transfer of computer program from one place to another place.Non-transient storage medium can be any available medium that can be accessed by general or special-purpose computer.By way of example and not limitation, non-transient computer-readable medium can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage device, disk storage device or other magnetic storage device, or can be used for carrying or storing desired program code member and can be accessed by general or special-purpose computer or general or special-purpose processor in the form of instruction or data structure Any other non-transient medium.In addition, any connection is appropriately referred to as computer-readable medium.For example, if software is sent from website, server or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL or wireless technology such as infrared, radio and microwave are included in the definition of computer-readable medium. As used herein, disk and disc include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0291] As used herein (including in the claims), "or" used in a list of items (e.g., a list of items introduced by a phrase such as "at least one of..." or "one or more of...") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). In addition, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an example step described as "based on condition A" may be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on".

[0292] The term "determining" encompasses a wide variety of actions, and thus, "determining" may include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, database or other data structure), ascertaining, etc. Additionally, "determining" may include receiving (such as receiving information), accessing (such as accessing data in a memory), etc. Additionally, "determining" may include resolving, obtaining, selecting, choosing, establishing, and other such similar actions.

[0293] In the drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number to distinguish between the similar components. If only the first reference number is used in the specification, the description may apply to any of the similar components having the same first reference number, regardless of the second or other subsequent reference numbers.

[0294] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that may be implemented or within the scope of the claims. The term "example" as used herein means "used as an example, instance, or illustration," rather than "preferred" or "having advantages over other examples." The specific embodiments include specific details to provide an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some cases, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0295] The description herein is provided to enable one of ordinary skill in the art to implement or use the present disclosure. Various modifications to the present disclosure will be apparent to one of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A device for wireless communication, the device comprising: Memory; Transceiver; and At least one processor of a user equipment (UE), the at least one processor coupled to the memory and the transceiver, and the at least one processor configured to: receiving, via the transceiver, a channel state information reference signal from a plurality of transmission and reception points; transmitting, via the transceiver, a channel state information report based at least in part on receiving the channel state information reference signal, the channel state information report indicating a subset of transmit reception points selected from the plurality of transmit reception points for communicating with the UE; as well as Communicating with a subset of the transmission reception points is based at least in part on transmitting the channel state information report.

2. The apparatus of claim 1 , wherein the at least one processor is further configured to: A bitmap indicating a subset of the transmission and reception points used for communicating with the UE is transmitted in the channel state information report, wherein a size of the bitmap is proportional to the amount of the plurality of transmission and reception points.

3. The apparatus of claim 2, wherein the bitmap indicates a common subset of transmit / receive points used to communicate with the UE on multiple layers.

4. The apparatus of claim 2, wherein the bitmap indicates a respective subset of transmit / receive points for communicating with the UE on each of a plurality of layers.

5. The apparatus of claim 2, wherein the at least one processor is further configured to: An indication of a configuration is received, the indication being used to indicate in the bitmap a common subset of transmit-receive points for communicating with the UE on a first plurality of layers, or a corresponding subset of transmit-receive points for communicating with the UE on each layer of a second plurality of layers.

6. The apparatus of claim 1, wherein the at least one processor is further configured to: A common selection of a spatial domain basis for each transmit-receive point in the subset of transmit-receive points is transmitted in the channel state information report for use in communicating with the UE on multiple layers.

7. The apparatus of claim 1, wherein the at least one processor is further configured to: A respective selection of a spatial domain basis for each transmit-receive point in the subset of transmit-receive points is transmitted in the channel state information report for communicating with the UE on each of a plurality of layers.

8. The apparatus of claim 1, wherein the amount of spatial domain basis indicated in the channel state information report is constant for each transmit-receive point in the subset of transmit-receive points.

9. The apparatus of claim 1, wherein the spatial domain basis quantity for a transmission-reception point in the subset of transmission-reception points indicated in the channel state information report is based at least in part on the transmission-reception point.

10. The apparatus of claim 1, wherein the at least one processor is further configured to: receiving an indication of a configuration of an amount of spatial domain basis to be indicated in the channel state information report; and The spatial domain basis quantity included in the channel state information report for each transmission reception point in the subset of transmission reception points is transmitted in the channel state information report.

11. The apparatus of claim 1 , wherein the at least one processor is further configured to: A respective number of the selected frequency domain bases for each of a plurality of layers is transmitted in the channel state information report based at least in part on a number of transmit-receive points selected for communicating with the UE on the layer.

12. The apparatus of claim 1, wherein the at least one processor is further configured to: A common selection of a spatial domain basis for each of the subset of transmit-receive points is sent in the channel state information report for each of a plurality of layers for communicating with the UE.

13. The apparatus of claim 1, wherein the at least one processor is further configured to: transmitting in the channel state information report selected non-zero coefficients for precoding for a first polarization at a first transmit-receive point in the subset of transmit-receive points, wherein the first polarization is stronger than a second polarization at the first transmit-receive point; transmitting in the channel state information report first two or more differential magnitudes between the selected non-zero coefficient and coefficients used for precoding for a second polarization at each transmit-receive point in the subset of transmit-receive points; as well as A second one or more differential magnitudes between the selected non-zero coefficients and coefficients used for pre-decoding at each of the subset of the transmission / reception points other than the first transmission / reception point are transmitted in the channel state information report.

14. The apparatus of claim 13, wherein the at least one processor is further configured to: An indication of whether the first polarization or the second polarization is stronger for each transmit-receive point in the subset of transmit-receive points is sent in the channel state information report.

15. The apparatus of claim 1, wherein the at least one processor is further configured to: transmitting, in the channel state information report for a first transmission reception point in the subset of transmission reception points, selected non-zero coefficients for precoding for a first polarization at the first transmission reception point; and One or more differential magnitudes between the selected non-zero coefficients and coefficients used for precoding for a second polarization at the first transmit / receive point are transmitted in the channel state information report for the first transmit / receive point.

16. The apparatus of claim 1, wherein the at least one processor is further configured to: A coherent joint transmission is received from the subset of transmit-receive points, wherein phases of a plurality of transmissions forming the coherent joint transmission are controlled and coordinated by the subset of transmit-receive points.

17. An apparatus for wireless communication at a network entity, the apparatus comprising: Memory; Transceiver; and at least one processor of the network entity, the at least one processor being coupled to the memory and the transceiver, and the at least one processor being configured to: Sending a channel state information reference signal; receiving a channel state information report based at least in part on transmitting the channel state information reference signal, the channel state information report indicating a subset of transmit reception points selected from a plurality of transmit reception points for communicating with a user equipment (UE); as well as Communicating with the UE based at least in part on receiving the channel state information report.

18. The apparatus of claim 17, wherein the at least one processor is further configured to: A bitmap indicating a subset of the transmission and reception points used for communicating with the UE is received in the channel state information report, wherein a size of the bitmap is proportional to a quantity of the plurality of transmission and reception points.

19. The apparatus of claim 18, wherein the bitmap indicates a common subset of transmit-receive points used to communicate with the UE on multiple layers.

20. The apparatus of claim 18, wherein the bitmap indicates a respective subset of transmit / receive points for communicating with the UE on each of a plurality of layers.

21. The apparatus of claim 18, wherein the at least one processor is further configured to: An indication of a transmission configuration is used to indicate in the bitmap a common subset of transmission reception points used to communicate with the UE on the first multiple layers, or a corresponding subset of transmission reception points used to communicate with the UE on each layer of the second multiple layers.

22. The apparatus of claim 17, wherein the at least one processor is further configured to: A common selection of a spatial domain basis for each of the subset of transmission reception points for communicating with the UE on multiple layers is received in the channel state information report.

23. The apparatus of claim 17, wherein the at least one processor is further configured to: A respective selection of a spatial domain basis for each of the subset of transmit-receive points for communicating with the UE on each of a plurality of layers is received in the channel state information report.

24. The apparatus of claim 17, wherein the amount of spatial domain basis indicated in the channel state information report is constant for each transmit-receive point in the subset of transmit-receive points.

25. The apparatus of claim 17, wherein the spatial domain basis quantity for a transmission reception point in the subset of transmission reception points indicated in the channel state information report is based at least in part on the transmission reception point.

26. The apparatus of claim 17, wherein the at least one processor is further configured to: sending an indication of a configuration of an amount of spatial domain basis to be indicated in the channel state information report; and Receive in the channel state information report a quantity on a spatial domain basis included in the channel state information report for each of the subset of transmission reception points.

27. The apparatus of claim 17, wherein the at least one processor is further configured to: A respective number of selected frequency domain bases for each of a plurality of layers is received in the channel state information report based at least in part on a number of transmit-receive points selected for communicating with the UE on the layer.

28. The apparatus of claim 17, wherein the at least one processor is further configured to: A common selection of a spatial domain basis for each transmit-receive point in a subset of the transmit-receive points is received in the channel state information report for each layer of a plurality of layers for communicating with the UE.

29. A method for wireless communication at a user equipment (UE), the method comprising: receiving a channel state information reference signal from a plurality of transmission and reception points; transmitting a channel state information report based at least in part on receiving the channel state information reference signal, the channel state information report indicating a subset of transmit reception points selected from the plurality of transmit reception points for communicating with the UE; as well as Communicating with a subset of the transmission reception points is based at least in part on transmitting the channel state information report.

30. A method for wireless communication at a network entity, the method comprising: Sending a channel state information reference signal; receiving a channel state information report based at least in part on transmitting the channel state information reference signal, the channel state information report indicating a subset of transmit reception points selected from a plurality of transmit reception points for communicating with a user equipment (UE); as well as Communicating with the UE based at least in part on receiving the channel state information report.

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